Answer:
Friction of the road on the motorcycle in the opposite direction
Explanation:
Khanacademy
Why are stars considered to be the building blocks of the universe?
A. Stars are found throughout the galaxy
B. Stars become novas, supernovas, and Black Holes
C. Nuclear fusion within stars creates needed elements for he universe
D. The sun is a star
A child and sled with a combined mass of 48.8 kg slide down a frictionless hill that is 7.05 m high. If the sled starts from rest, what is its speed at the bottom of the hill?
___m/s
Answer:
Speed at bottom of the hill (v) = 11.74 m/s
Explanation:
Given:
Combined mass = 48.8 kg
Height h = 7.05 m
Find:
Speed at bottom of the hill (v)
Computation:
v² = 2gh
v = √2 x 9.8 x 7.05
v = √138.18
v = 11.74 m/s
Speed at bottom of the hill (v) = 11.74 m/s
*A car is going through a dip in the road whose curvature approximates a circle of radius 150m. At what velocity will the occupants of the car appear to weigh 15% more than their normal weight
Answer:
v= 14.85 m/s
Explanation:
When at the bottom of the dip, the only force that keeps the car in the circular trajectory, is the centripetal force.This force is not a new force, is just the net force aiming to the center of the circle.In this case, is just the difference between the normal force (always perpendicular to the surface, pointing upward) and the force that gravity exerts on the car (which is known as the weight), pointing downward.So, we can write the following expression:[tex]F_{cent} = F_{n} - F_{g} (1)[/tex]
It can be showed that the centripetal force is related to the speed by the following expression:[tex]F_{cent} = m*\frac{v^{2}}{r} (2)[/tex]The normal force, it is called the apparent weight, because it would be the weight as measured by a scale.Replacing (2) in (1), and solving for Fn, we get:[tex]F_{n} = m*\frac{v^{2} }{r} + m*g (3)[/tex]
Now, we need to find the value of v that makes Fn, exactly 15% more than the weight m*g, so we can write the following equation:[tex]F_{n} = 1.15*F_{g} = m*\frac{v^{2}}{r} +F_{g} (4)[/tex]
Replacing Fg by its value, simplifying, and solving for v, we get:[tex]v = \sqrt{0.15*g*r} = \sqrt{9.8 m/s2*0.15*150m} = 14.85 m/s (5)[/tex]
Why does the sun predictably hold the asteroid and the Earth in orbit?
Answer:
The force of gravity
Explanation:
The sun is able to predictably hold the asteroid and the earth in orbit by the force of gravity is possesses.
During the earth formation of the solar system, the sun captured the earth and other planetary bodies within its region of influence.
Based on Newton's law of universal gravitation, the force of gravity between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. The sun is a very massive body and due to the mass of the earth and other bodies, they are captured by the attractive gravitational force into its orbit.i need help on number 6 pls due today
Explanation:
Graph A matches description 4 because the car is coming back.
Graph B matches description 3 because the speed of the car is decreasing.
Graph C matches the description 2 because the car is traveling at a constant rate.
Graph D matches the description 1 because the car is stopped.
_______ is the most common pollutant; we often simply refer to it
as "smog".
Ground-level ozone is the most common pollutant that is often referred to as "smog".
What is smog?Smog is a type of air pollution that is characterized by a mixture of smoke and fog.
It typically forms in urban areas with high levels of vehicle and industrial emissions, as well as natural factors such as temperature inversions.
Smog is composed of a complex mixture of pollutants, including ground-level ozone, nitrogen oxides, sulfur oxides, particulate matter, and volatile organic compounds (VOCs).
Exposure to smog can cause a range of health problems, including respiratory issues, heart disease, and cancer. It can also have negative impacts on the environment, including damage to crops, forests, and bodies of water. Efforts to reduce smog often involve reducing emissions from vehicles and industrial sources and promoting cleaner forms of transportation and energy production.
Therefore, The Ground-level ozone is the most common pollutant that is often referred to as "smog".
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What does a producer need to make its own food
Answer:
A producer needs the sun to make its own food, because producers use photosynthesis. In photosynthesis you use the sun to turn the air people breathe out and water into glucose and oxygen.
Explanation:
Hope this helps ^-^
If you tethered a space station to the earth by a long cable, you could get to space in an elevator that rides up the cable--much simpler and cheaper than riding to space on a rocket. There's one big problem, however: There is no way to create a cable that is long enough. The cable would need to reach 36,000 km upward, to the height where a satellite orbits at the same speed as the earth rotates; a cable this long made of ordinary materials couldn't even support its own weight. Consider a steel cable suspended from a point high above the earth. The stress in the cable is highest at the top; it must support the weight of cable below it.
What is the greatest length the cable could have without failing? For the purposes of this problem, you can ignore the variation in gravity near the surface of the earth. Hint: The mass of the cable is the volume of the cable multiplied by the density. The density of steel is 7900 kg/m3.
Answer:
[tex]Stress=12903.3923m[/tex]
Explanation:
From the question we are told that
Cable length 36,000km
The density of steel is 7900 kg/m3.
Generally mass is mathematically given as
[tex]m= \rho v[/tex]
[tex]m= \rho Al[/tex]
Generally the weight of cable is mathematically give as
[tex]W_c=mg[/tex]
[tex]W_c=(\rho Al)g[/tex]
Generally the stress on a material is mathematically represented as
[tex]Stress=\frac{Force}{Area}[/tex]
[tex]Stress=\frac{\rho Al}{A}*g[/tex]
[tex]Stress=\frac{\rho l}{1}*g[/tex]
Stress or tensile strength of steel is [tex]1000*10^6N/m^2[/tex]
Therefore
[tex]l=\frac{Stress}{pg}[/tex]
[tex]Stress=\frac{1000*10^6}{(7900)(9.81)}[/tex]
[tex]Stress=12903.3923m[/tex]
[tex]Stress=12903.4m\ appro[/tex]
In order to track the movement of Earth’s tectonic plates over time, scientists use which of the following tools?
A) estimating
B) rulers
C) digitized signals from GPS
Sonar is a device that uses reflected sound waves to measure underwater depths. If a sonar signal has a frequency of 288 Hz, and the wavelength is 5.00 m, what is the speed of the sonar signal in water?
Given that,
The frequency of a sonar signal, f = 288 Hz
Wavelength = 5 m
To find,
The speed of the sonar signal in water.
Solution,
Let the speed of the sonar signal is v. The speed in terms of wavelength and frequency is given by :
[tex]v=f\lambda\\\\v=288\times 5\\\\v=1440\ m/s[/tex]
So, the speed of the sonar signal in water is 1440 m/s.
A cannonball is launched off a 100 m cliff horizontally with an initial velocity of 50
m/s. The goal is to hit a target 200m away but the cannonball goes too far. Which of
these changes could make the cannonball travel a shorter distance?
a) Decrease the launch speed of the cannon.
UbNeither of these will decrease the range of the cannonball
d Both of these will decrease the range of the cannonball
Lower the launch height of the cannon.
Answer:
the correct one is b, Decrease the launch speed and Low the launch height
Explanation:
Let's find the solution to the problem in order to answer the questions.
The bullet is fired horizontally with a velocity vo, let's find the time or it takes to reach the ground
y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
as it shoots horizontally v_{oy} = 0 and when I reach the floor y = 0
0 = y₀ - ½ g t2
t = [tex]\sqrt{\frac{2y_{o} }{g} }[/tex]
where y₀ is the height of the cliff
at this time the bullet recreates a distance of
x = v₀ t
we substitute
x = v₀ \sqrt{\frac{2y_{o} }{g} }
There, to reduce the range of the bullet, we must decrease its speed. This is the magnitude that most affects the distance and to a lesser degree we can decrease the height.
When checking the answers, the correct one is b
35. The work function of
Caesium is 2.14 e V. The
threshold frequency for
Caesium is
*
Answer:
[tex]5.16*10^{14}Hz[/tex]
Explanation:
1 eV = 1.6 * 10⁻¹⁹ J
The work function is the minimum energy required to cause the photo-emission of electrons. The work function is dependent on the type of metal.
Whereas the threshold frequency is the minimum frequency of light required to produce the work function energy. The work function is given by:
[tex]E=hf_o\\\\Where\ E = work \ function, h=plank's\ constant=6.63*10^{-34}Js,f=threshold\ frequency.\\\\Given\ that \ E=2.14eV, hence:\\\\E=hf_o\\\\2.14eV=6.63*10^{-34}Js*f_o\\\\f_o=\frac{2.14\ *1.6*10^-19}{6.63*10^{-34}Js} \\\\f_o=5.16*10^{14}Hz[/tex]
The diagrams below represent different ways heat can be transferred on Earth. The arrows in the diagrams show the direction of heat transfer.
Which of the following shows the primary way heat is transferred in each diagram?
A)
Diagram X = conduction; Diagram Y= convection; Diagram Z = radiation
B)
Diagram X = convection; Diagram Y = radiation; Diagram Z = conduction
C)
Diagram X = convection; Diagram Y = conduction; Diagram Z = radiation
Answer:
c
Explanation:
heat radiates off of thing most of the time
Diagram X = convection; Diagram Y = conduction; Diagram Z = radiation
What are the 3 ways heat is transferred on Earth?radiation.conduction.convection.What is the direction of flow of heat transfer?The direction of heat transfer is first from the lower-temperature object to the higher-temperature object, then back again to the lower-temperature object, and so forth, until the objects are in thermal equilibrium.
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1. The combined forces acting on an object make up the _____ force.
Answer:
Which has the most energy stored as heat?
a cup of ice
a bathtub of cold water
a cup of boiling water
a bucket of ice water
When the car is sitting and not moving, inertia is in control and ___
exists.
6. Calculate the total resistance in a series circuit with a fan (3 ohms) and 3 lights (1 ohms each).
15 ohms
6 ohms
12 ohms
9 ohms
PLS HURRY ILL MARK BRAINLYEST
Answer:
R_eq = 6 Ω
Explanation:
In a series circuit the current is constant throughout the circuit and the resistance is the sum of all the resistances in it.
R_eq = ∑ [tex]R_{i}[/tex]
in this case we have
R_eq = R₁1 + 3 R₂
where R₁ is the resistance of the fan and R₂ the resistance of each light, we must clarify that we will assume that the resistance of the lights does not change with temperature
let's calculate
R_eq = 3 + 3 1
R_eq = 6 Ω
Answer:
The awnser is 6 ohms.
Explanation:
Suppose you are traveling down the highway at 100 km/hr, and want to pass a truck. You accelerate from 100 km/hr to 120 km/hr in 3 seconds in order to do so. What is your average acceleration, in meters per second squared (m/s 2 )
Answer:
1.87 ms-2
Explanation:
We need to convert the velocity from km/hr to m/s as follows;
100 × 1000/3600 = 27.7 m/s
Also
120 × 1000/3600 = 33.3 m/s
From;
v= u + at
v= 33.3 m/s
u= 27.7 m/s
t= 3 secs
v= u + at
a = v- u/t
a = 33.3 - 27.7/3
a= 1.87 ms-2
0-kilogram child moving at 4.0 meters per second jumps onto a 50-kilogram sled that is initially at rest on a long, frictionless, horizontal sheet of ice. [INF] a. Determine the speed of the child-sled system after the child jumps onto the sled. b. After coasting at constant speed for a short time, the child jumps off the sled in such a way that she is at rest with respect to the ice. Determine the speed of the sled after the child jumps off
This question is incomplete, the complete question is;
A 30-kilogram child moving at 4.0 meters per second jumps onto a 50-kilogram sled that is initially at rest on a long, frictionless, horizontal sheet of ice.
a. Determine the speed of the child-sled system after the child jumps onto the sled.
b. After coasting at constant speed for a short time, the child jumps off the sled in such a way that she is at rest with respect to the ice. Determine the speed of the sled after the child jumps off
Answer:
a) the speed of the child-sled system after the child jumps onto the sled is 1.5 m/s
b) the speed of the sled after the child jumps off is 2.4 m/s
Explanation:
Given that;
Weight of the child m_c = 30 kg
u = 4 m/s
M = 50 kg
a) the speed of the child-sled system after the child jumps onto the sled.
Using conservation of momentum;
P_i = P_f
30 × 4 = 50(v) + 30(v)
120 = 80(v)
v = 120 / 80
v = 1.5 m/s
therefore, the speed of the child-sled system after the child jumps onto the sled is 1.5 m/s
b) the speed of the sled after the child jumps off .
Also using conservation of momentum;
mv1 = mv2
(30+50) × 1.5 = (30 × 0) + (50 × v2 )
80 × 1.5 = 50v2
v2 = 120 / 50
v2 = 2.4 m/s
Therefore the speed of the sled after the child jumps off is 2.4 m/s
A ball starts from rest, it rolls down a ramp and reaches the ground after 4 seconds. The final velocity when it reaches the ground is 7.0 meters/second. What is initial velocity and its acceleration?
If it starts at rest the initial velocity is 0.
For an acceleration, a, and time, t, the velocity is v=at. Since at t=4, v=7, then a=7/4=1.75m/s^2
The initial velocity and the acceleration of the ball start from rest, it rolls down a ramp and reaches the ground after 4 seconds are 0 m/s and 3.5 m / s² respectively.
What is velocity?The rate of change of an object's location when viewed from a particular angle and measured in a particular unit of time is known as its velocity.
The average speed of a point for a set period of time while it travels a predetermined distance along its path is equal to the distance traveled divided by the travel time. A train, for instance, moves at an average speed of 50 km/h when it travels 100 km in two hours.
Given:
A ball starts from rest, it rolls down a ramp and reaches the ground after 4 seconds. The final velocity when it reaches the ground is 7.0 m/s,
Calculate the acceleration as shown below,
[tex]v = u + at[/tex]
7 = u + a × 4
7 = u + 4a
As it starts from rest, then the initial velocity is 0 m/s
a = 7/4 or 3.5 m / s²
Thus, the acceleration is 3.5 m / s² and the initial velocity is 0 m/s.
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Which of the following has the most momentum? proton (m=1.67 x 10-27 kg) moving at 2.0 x 104 m/s,an electron (m=9.11 x 10-31 kg) moving at 2.0 x 106 m/s, a common house fly (m=12 mg) moving at 2.0 m/s, North American tectonic plate (m≈5x1022 kg) moving at 3.0x10-10 m/s (about 1cm/yr)
Answer:
The North American tectonic plate.
Explanation:
recall the formula for momentum: p = m * v
the subatomic particles have very small masses while high speeds, so the product results in values with negative exponents in scientific notation.
Negative exponents also result for the house fly when converting mg into kg (10^-6).
The positive exponents in scientific notation for the momentum come for the gigantic mass of the continental plate which exceeds the negative exponents contributed by the small velocity.
Which players are usually the fasted on the team, run the offensive, and shoot from the perimeter of the court?
Forward
Mid-fielder
Guard
Center
Answer:
i think guard but not sure
An object travels in a circular path at speed vand experiences a centripetal acceleration ac. What will be the object's new centripetal
acceleration, if its speed is increased to 2.0V?
Answer:
Option B. 4a꜀
Explanation:
From the question given above, the following data were obtained:
Initial speed (v₁) = v
Initial acceleration (a₁) = a꜀
New speed (v₂) = 2v
New acceleration (a₂) =?
Centripetal acceleration is given by the following equation:
a = v²/ r
Next, we shall make r the subject.
a = v²/ r
Cross multiply
a × r = v²
Divide both side by a
r = v² / a
NOTE: We assume the radius (r) to be constant.
v₁² / a₁ = v₂² / a₂
Thus, we shall determine the new acceleration as follow:
Initial speed (v₁) = v
Initial acceleration (a₁) = a꜀
New speed (v₂) = 2v
New acceleration (a₂) =?
v₁² / a₁ = v₂² / a₂
v² / a꜀ = (2v)² / a₂
v² / a꜀ = 4v² / a₂
Cross multiply
v² × a₂ = a꜀ × 4v²
Divide both side by v²
a₂ = a꜀ × 4v² / v²
a₂ = a꜀ × 4
a₂ = 4a꜀
Therefore, the new centripetal acceleration of the object is 4a꜀
Answer:
4.0 · ac
Explanation:
Just did it
Which of the following best describes a galaxy?
A. A spiral shape of stars
B. Large groups of stars held together by gravity
C. The Milky Way
D. The rotation of many planets and stars
Answer:
B-Large groups of stars held together by gravity
Explanation:
How does the atmosphere affect the hydrosphere?
Answer:
when pure water vapor from the water bodies get absorbed into polluted gases in the atmosphere, acid rain is caused and when this happens in a place where an element of the hydrosphere is located, it is polluted.in such a way hydrosphere is effected
Answer: When a parcel of air in the atmosphere becomes saturated with water, precipitation, such as rain or snow, can fall to Earth's surface.
Explanation:
Human contributions to greenhouse gases in the atmosphere are warming the earth's surface a process which is projected to increase evaporation of surface water and accelerate the hydrologic cycle. In turn, a warmer atmosphere can hold more water vapor.
Answer the question below:
Answer:
D) the decay rates of radioactive uranium and lead
Explanation:
As we know that when she found the substance it must have some fixed ratio of radioactive uranium and Lead in that substance.
Here since Uranium is radioactive substance so it will continuously convert into Lead and this ratio will change with time
So here we can say that the ratio of radioactive uranium and lead will depend on its decay rate
now to find the age of the substance we can find the present ratio of lead and uranium in that substance and then compare it with freshly prepared substance.
so by the formula
we can find the age of the sample
Answer:
Its D
Explanation:
A football is kicked with an initial speed of 11.0 m/s, at an angle of 35degrees above the horizontal across horizontal ground.
(Assume air resistance is negligible)
What is the range of the ball?
Answer:
The range of the ball is 11.6 meters
Explanation:
Projectile Motion
It's the type of motion that experiences an object launched with an initial angle and moves along a curved path exclusively under the action of gravity.
Being vo the initial speed of the object, θ the initial launch angle, and g the acceleration of gravity, then the maximum horizontal distance traveled by the object (also called Range) is:
[tex]\displaystyle d={\frac {v_o^{2}\sin(2\theta )}{g}}[/tex]
The football is kicked with an initial speed of vo=11 m/s at an angle of θ=35°.
Calculating the range:
[tex]\displaystyle d={\frac {11^{2}\sin(2\cdot 35^\circ)}{9.8}}[/tex]
[tex]\displaystyle d={\frac {121\sin(70^\circ)}{9.8}}[/tex]
d = 11.6 m
The range of the ball is 11.6 meters
If an object doubles its speed, how much does its kinetic energy go up by? What if it triples its speed?
Answer:
Kinetic energy is the energy of motion. An object that has motion - whether it is vertical or horizontal motion - has kinetic energy. There are many forms of kinetic energy - vibrational (the energy due to vibrational motion), rotational (the energy due to rotational motion), and translational (the energy due to motion from one location to another). To keep matters simple, we will focus upon translational kinetic energy. The amount of translational kinetic energy (from here on, the phrase kinetic energy will refer to translational kinetic energy) that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object. The following equation is used to represent the kinetic energy (KE) of an object.
KE = 0.5 • m • v2
where m = mass of object
v = speed of object
This equation reveals that the kinetic energy of an object is directly proportional to the square of its speed. That means that for a twofold increase in speed, the kinetic energy will increase by a factor of four. For a threefold increase in speed, the kinetic energy will increase by a factor of nine. And for a fourfold increase in speed, the kinetic energy will increase by a factor of sixteen. The kinetic energy is dependent upon the square of the speed. As it is often said, an equation is not merely a recipe for algebraic problem solving, but also a guide to thinking about the relationship between quantities.
Kinetic energy is a scalar quantity; it does not have a direction. Unlike velocity, acceleration, force, and momentum, the kinetic energy of an object is completely described by magnitude alone. Like work and potential energy, the standard metric unit of measurement for kinetic energy is the Joule. As might be implied by the above equation, 1 Joule is equivalent to 1 kg*(m/s)^2.
1 Joule = 1 kg • m2/s2
Explanation:
What is the voltage across a load that has a resistance of 7.5 ohms and a 1.8 A current flowing through it? *
Answer:
13.5V
Explanation:
u=i*r
u=1.8×7.5=13.5V
Can someone help me god will bless you
Answer:
Symbolic culture, or nonmaterial culture, is the ability to learn and transmit behavioral traditions from one generation to the next by the invention of things that exist entirely in the symbolic realm. Symbolic culture is studied by archaeologists, social anthropologists and sociologists.
Explanation:
i hope this helped!