Answer:
B
Explanation:
Predicted height and total energy
Answer:
The predicted height is 2.809 meters, writing this in centimeters we get (1m = 100cm):
h = 2.809 m = (2.809)*(100cm) = 280.9 cm
And the total energy is:
E = 6.696 J
Explanation:
First let's see the problem.
We have an object of mass m = 274g which is thrown upwards with an initial velocity v0 = 6.991 m/s, in a place with a gravitational acceleration of g = 8.7 m/s^2
When the object is on the air, the only force acting on it will be the gravitational force, then the acceleration of the object will be equal to the gravitational acceleration, then we can write:
a(t) = -8.7 m/s^2
Where the negative sign is because this acceleration points down.
Now to get the velocity of the object we can integrate over time to get:
v(t) = (-8.7 m/s^2)*t + v0
Where v0 is a constant of integration, which is the initial velocity, then we can write this as:
v(t) = (-8.7 m/s^2)*t + 6.991 m/s
Now we can integrate again over the time to get the position equation.
p(t) = (1/2)*(-8.7 m/s^2)*t^2 + (6.991 m/s)*t + p0
Where p0 is the initial position, because the ball is being thrown from the ground, the initial position is 0.
Then the position equation is:
p(t) = (1/2)*(-8.7 m/s^2)*t^2 + (6.991 m/s)*t
Ok, now we know all the movement equations for the object.
The first thing we want to know is the maximum height of the object.
We know that the object reaches its maximum height when the velocity is zero (this is, the velocity stops being positive, meaning that the object stops going up, then in that time we have the maximum height)
We need to solve:
v(t) = 0m/s = (-8.7 m/s^2)*t + 6.991 m/s
(8.7 m/s^2)*t = 6.991 m/s
t = 6.991 m/s/( (8.7 m/s^2) = 0.804 seconds
The maximum height of the object is given by:
p(0.804s) = (1/2)*(-8.7 m/s^2)*(0.804)^2 + (6.991 m/s)*(0.804) = 2.809 m
The maximum height of the object is 2.809 meters.
Now let's find the maximum energy.
Remember that the energy of an object can be written as the sum of the potential energy U and the kinetic energy K.
E = K + U
Such that for an object of mass m and velocity v, the kinetic energy is:
K = (1/2)*m*v^2
And for an object of mass m, at a height h from the ground and with gravitational acceleration g, the potential energy is:
U = m*g*h
Now, when the object is at its maximum height, the velocity is zero.
Then K = 0
And for conservation of energy, the total energy of the object becomes potential energy.
E = 0 + U
E = U
So if we find the potential energy at the maximum height of the object's path, we can find the total energy of the object.
We know that:
mass = m = 274g = 0.274 kg (here i used that 1kg = 1000g)
height = h = 2.809 meters.
gravitational acceleration = g = 8.7 m/s^2
Then the potential energy at this point is:
U = 0.274 kg*(2.809 meters)*(8.7 m/s^2) = 6.696 J
This means that the total energy of the object is:
E = 6.696 J
Question 7 of 11
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A 1655 kg car drives down the highway. If the car has a momentum of 61250 kg. m/s, what is the velocity of the car?
Answer:
velocity = 37.01 m/s
Explanation:
momentum = mass * velocity
61250 = 1655 * x
x = 61250 / 1655
x = 37.0090634441
Explain, step by step, how to calculate the amount of current (I) that will go through the resistor in this circuit
Answer:
0.03 A
Explanation:
From the question given above, the following data were obtained:
Voltage (V) = 12 V
Resistor (R) = 470 Ω
Current (I) =?
From ohm's law, the voltage, current and resistor are related by the following formula:
Voltage = current × resistor
V = IR
With the above formula, we can obtain the current in the circuit as follow:
Voltage (V) = 12 V
Resistor (R) = 470 Ω
Current (I) =?
V = IR
12 = I × 470
Divide both side by 470
I = 12 / 470
I = 0.03 A
Thus, the current in the circuit is 0.03 A
Answer:
0.03 A
Explanation:
Explain, step by step, how to calculate the amount of current (I) that will go through the resistor in this circuit
0.03 A
At which point is there the most potential energy? At which point is there the most kinetic energy?
A. Potential energy A; Kinetic energy B
B. Potential energy B; Kinetic energy D
C. Potential energy A; Kinetic energy D
D. Potential energy C; Kinetic energy D
Answer:
The cart mark (a) has the most potential energy and the cart marked (b) has the most kinetic energy
Find the wavelength of light which is capable of ionizing a hydrogen atom?
Answer:
The correct answer is - 91.4 nm
Explanation:
According to Bohr's model, the minimum wavelength to ionize Hydrogen atom from n= 1 state is expressed as:
(h×c)/λ=13.6eV
here,
h - Planck constant
c - the speed of light
λ - wavelength
Placing the value in the formula for the wavelength
(6.626×10^−34J.s × 3×10^8 m/s)/λ = 13.6 ×1.6 × 10^−19 J
λ≈91.4nm
Thus, the correct answer would be = 91.4 nm
Help me with this review question please.
Answer:
K E=( mv²)/2
=(60×3.5²)/2
=367.5J
If each Coulomb of charge is given 20 Joules of energy, what is the voltage of the battery?
A. 20 V
B. 5 V
C. 10 V
D. Not enough info
Answer:
Explanation:
V = J/C
V = 20/1
= 20 v
Option A is the correct answer
We have seen that the voltage of a concentration cell can be affected by the concentrations of aqueous components and/or temperature. The identity of the redox pair also affects the observed voltage of a concentration cell in a somewhat subtle way. Carefully consider the Nernst equation. Rank the redox pairs below from greatest (1) to smallest (3) voltage in a concentration cell, assuming equal values of T and Q for all cells. Assume multimeter leads are connected to that measured voltages are positive.
a. Copper metal/copper(l) ion
b. Aluminum/aluminum ion
c. Magnesium metal/magnesium ion
Answer:
1) Magnesium metal/magnesium ion
2) Aluminum/aluminum ion
3) Copper metal/copper(l) ion
Explanation:
The activity series is a series that shows the ease of reactivity of substances in an electrochemical cell.
The substances that are higher up in the series are more reactive in electrochemical cells.
Magnesium is the first element in the series that has the most negative redox potential then followed aluminium.
Hence, according to Nernst,
1) Magnesium metal/magnesium ion
2) Aluminum/aluminum ion
3) Copper metal/copper(l) ion
Which device converts electric energy into mechanical energy?
O A. An electromagnet
O B. A motor
O C. A transformer
O D. A generator
Answer:
B motor
Explanation:
lus
A cup has a mass of 0.0650 kg and a
volume of 0.000250 m3, and is floating
in fresh water. Pennies are put into the
cup until the top of the cup is level with
the water line. What is the mass of the
pennies in the cup?
[?] kg
Pwater = 1,000 kg/m3
Answer:
hey but the person at the top is right
Answer:
0.185
Explanation:
Volume of water displaced = 0.000250 ( volume of cup )
Mass of water displaced by cup = density of water X volume of water displaced
= 1000 X 0.000250 = 0.250 kg
Mass of water displaced = mass of cup + mass of pennies ( law of flotation)
0.25 = 0.0650 + mass of pennies
Mass of pennies = 0.2500 - 0.0650
= 0.185 kg
Don’t hesitate to like and rate this answer. It would mean a lot for me.
Credit-Card Magnetic Strips Experiments carried out on the television show Mythbusters determined that a magnetic field of 1000 gauss is needed to corrupt the information on a credit card's magnetic strip. (They also busted the myth that a credit card can be demagnetized by an electric eel or an eelskin wallet.) Suppose a long, straight wire carries a current of 7.0A . How close can a credit card be held to this wire without damaging its magnetic strip?
Answer:
14 μm
Explanation:
The magnetic field due to a long straight wire is B = μ₀i/2πr where μ₀ = permeability of free space = 4π × 10⁻⁷ H/m, i = current = 7.0 A and r = distance of credit card from magnetic field.
So r = μ₀i/2πB since B = 1000 gauss = 1000 G × 1 T/10000 G = 0.1 T
r = 4π × 10⁻⁷ H/m × 7.0 A/(2π × 0.1 T)
r = 2 × 10⁻⁷ H/m × 7.0 A/0.1 T
r = 14 × 10⁻⁷ H/m × A/0.1 T
r = 140 × 10⁻⁷ m
r = 1.4 × 10⁻⁵ m
r = 14 × 10⁻⁶ m
r = 14 μm
A mom pushes her 19.3 kg daughter on the swing. If she gives her an initial velocity of 7.5 m/s at the bottom of the swing and the swing sits 0.6 m above the ground at it's lowest point, what height does she reach above the ground?
Answer:
3.17333333333? I hope I get it right
Explanation:
..................hello
Select the correct answer Which object is an insulator
A. iron
b. cooper
c. plastic
d. salt water
Which of the following could be an example of chemical weathering?
a. rocks tumbling against each other
b. water seeping into the ground, dissolving the limestone to form a cave
c. a waterfall boring out a whole in a rock under it
Answer: B
Explanation:
Answers A and C are examples of physical weathering while B is chemical weathering when water and lime mix it creates a reaction
A wire carries a current of 4.2 A at what distance from the wire does the magnetic field have a magnitude of 1.3×10^ -5 t
Answer:
the distance is 6.46 cm.
Explanation:
Given
current in the wire, I = 4.2 A
magnitude of the magnetic field, B = 1.3 x 10⁻⁵ T
The distance from the wire is determined by using Biot-Savart Law;
[tex]B = \frac{\mu_o I}{2\pi r} \\\\r = \frac{\mu_o I}{2\pi B}[/tex]
Where;
r is the distance from the wire where the magnetic field is experienced
[tex]r = \frac{\mu_o I}{2\pi B}\\\\r = \frac{4\pi \times 10^{-7} \times 4.2 }{2\pi \times 1.3 \times 10^{-5}}\\\\r = 0.0646 \ m\\\\r = 6.46 \ cm[/tex]
Therefore, the distance is 6.46 cm.
A ball weighs 5.7 N on Earth. What is its mass?
Answer:
55.897905
Explanation:
1 Newton in Earth gravity is the equivalent weight of 1/9.80665 kg on Earth
9.80665 times 5.7=55.897905
Brainliest?
A man walks 30 m to the west, then 5 m to the east in 45 seconds.
What is his average speed?
What is the order of the events for the water cycle on a typical warm day?
А
rain, snow, sleet
B
precipitation, evaporation, rain
с
evaporation, condensation, precipitation
D
condensation, evaporation, precipitation
A 2.0-kg cart is rolling along a frictionless, horizontal track towards a 1.8-kg cart that is held initially at rest. The carts are loaded with strong magnets that cause them to attract one another. Thus, the speed of each cart increases. At a certain instant before the carts collide, the first cart's velocity is 5.9 m/s, and the second cart's velocity is -2.7 m/s. (a) What is the total momentum of the system of the two carts at this instant
Answer:
the total momentum of the system before collision is 6.94 kgm/s
Explanation:
Given;
mass of the first cart, m₁ = 2.0 kg
mass of the second cart, m₂ = 1.8 kg
velocity of the first cart before collision, u₁ = 5.9 m/s
velocity of the second cart before collision, u₂ = -2.7 m/s
The total momentum of the system before collision is calculated as follows;
[tex]P_t = P_1 + P_2 \\\\P_t = m_1u_1 + m_2u_2\\\\P_t = (2\times 5.9) + (1.8 \times -2.7)\\\\P_t = 11.8 - 4.86\\\\P_t = 6.94 \ kgm/s[/tex]
Therefore, the total momentum of the system before collision is 6.94 kgm/s
Force of a Baseball Swing. A baseball has mass 0.153 kg . Part A If the velocity of a pitched ball has a magnitude of 44.5 m/s and the batted ball's velocity is 50.5 m/s in the opposite direction, find the magnitude of the change in momentum of the ball and of the impulse applied to it by the bat. Express your answer to three significant figures and include the appropriate units. P
Answer: 14.5 kg.m/s
Explanation:
Given
mass of baseball is [tex]m=0.153\ kg[/tex]
The initial speed of the ball is [tex]u=-44.5\ m/s[/tex]
the final speed of the ball is [tex]v=50.5\ m/s[/tex]
Impulse is given as a change in the momentum
[tex]\vec{J}=\Delta \vec{P}[/tex]
[tex]J=m(v-u)\\J=0.153(50.5-(44.5))\\J=0.153\times 95=14.535\ kg.m/s[/tex]
Change in momentum up to 3 significant figures is 14.5 kg.m/s
Impulse applied by a bat is also the same as the change in momentum
Pls help ASAP
Imagine that Maritans launch a rocket toward the Earth at a great speed. While the
rocket is traveling toward us, it will appear
than it actually is.
O more blue
darker
larger
more red
Answer:
The rocket will appear larger than it actually is
Fairly easy question I’ll give extra points help.
1. third law
2. first law
3. third law
4. second law
A solenoid that is 93.9 cm long has a cross-sectional area of 17.3 cm2. There are 1270 turns of wire carrying a current of 7.80 A. (a) Calculate the energy density of the magnetic field inside the solenoid. (b) Find the total energy in joules stored in the magnetic field there (neglect end effects).
Answer:
[tex]65.6\ \text{J/m}^3[/tex]
[tex]0.11\ \text{J}[/tex]
Explanation:
B = Magnetic field = [tex]\mu_0 \dfrac{N}{l}I[/tex]
[tex]\mu_0[/tex] = Vacuum permeability = [tex]4\pi10^{-7}\ \text{H/m}[/tex]
N = Number of turns = 1270
[tex]l[/tex] = Length of solenoid = 93.9 cm = 0.939 m
[tex]I[/tex] = Current = 7.8 A
A = Area of solenoid = [tex]17.3\ \text{cm}^2[/tex]
Energy density of a solenoid is given by
[tex]u_m=\dfrac{B^2}{2\mu_0}\\\Rightarrow u_m=\dfrac{(\mu_0 \dfrac{N}{l}I)^2}{2\mu_0}\\\Rightarrow u_m=\dfrac{\mu_0N^2I^2}{2l^2}\\\Rightarrow u_m=\dfrac{4\pi\times 10^{-7}\times 1230^2\times 7.8^2}{2\times 0.939^2}\\\Rightarrow u_m=65.6\ \text{J/m}^3[/tex]
The energy density of the magnetic field inside the solenoid is [tex]65.6\ \text{J/m}^3[/tex]
Energy is given by
[tex]U_m=u_mAl\\\Rightarrow U_m=65.6\times 17.3\times 10^{-4}\times 0.939\\\Rightarrow U_m=0.11\ \text{J}[/tex]
The total energy in joules stored in the magnetic field is [tex]0.11\ \text{J}[/tex].
The moon does not stay at the same distance from the earth.why?
Answer:
The moon does not stay at the same distance of the earth because the ortbit of the moon is slightly elliptical. If earth is not tilted at an angle of 66.5°, there will be no change in the season and the earth will have equal length of days and night.
Explanation:
mark me brainlest
g A thin-walled hollow cylinder and a solid cylinder, both have same mass 2.0 kg and radius 20 cm, start rolling down from rest at the top of an incline plane. The height of top of the incline plane is 1.2 m. Find translational speed of each cylinder upon reaching the bottom and determine which cylinder has the greatest translational speed upon reaching the bottom. Moment of inertia of hollow cylinder about its axis passing through the center is mr2 and for solid cylinder mr2/2
Answer:
a. i. 3.43 m/s ii. 2.8 m/s
b. The thin-walled cylinder
Explanation:
a. Find translational speed of each cylinder upon reaching the bottom
The potential energy change of each mass = total kinetic energy gain = translational kinetic energy + rotational kinetic energy
So, mgh = 1/2mv² + 1/2Iω² where m = mass of object = 2.0 kg, g =acceleration due to gravity = 9.8 m/s², h = height of incline = 1.2 m, v = translational velocity of object, I = moment of inertia of object and ω = angular speed = v/r where r = radius of object.
i. translational speed of thin-walled cylinder upon reaching the bottom
So, For the thin-walled cylinder, I = mr², we find its translational velocity, v
So, mgh = 1/2mv² + 1/2Iω²
mgh = 1/2mv² + 1/2(mr²)(v/r)²
mgh = 1/2mv² + 1/2mv²
mgh = mv²
v² = gh
v = √gh
v = √(9.8 m/s² × 1.2 m)
v = √(11.76 m²/s²)
v = 3.43 m/s
ii. translational speed of solid cylinder upon reaching the bottom
So, For the solid cylinder, I = mr²/2, we find its translational velocity, v'
So, mgh = 1/2mv'² + 1/2Iω²
mgh = 1/2mv² + 1/2(mr²/2)(v'/r)²
mgh = 1/2mv'² + mv'²
mgh = 3mv'²/2
v'² = 2gh/3
v' = √(2gh/3)
v' = √(2 × 9.8 m/s² × 1.2 m/3)
v' = √(23.52 m²/s²/3)
v' = √(7.84 m²/s²)
v' = 2.8 m/s
b. Determine which cylinder has the greatest translational speed upon reaching the bottom.
Since v = 3.43 m/s > v'= 2.8 m/s,
the thin-walled cylinder has the greatest translational speed upon reaching the bottom.
a Ferris wheel with a diameter of 35 m starts from rest and achieves its maximum operational tangential speed of 2.3 m/s in a time of 15 s. what is the magnitude of the wheels angular acceleration?
b. what is the magnitude of the tangential acceleration after the maximum operational speed is reached?
A carnival ride starts at rest and is accelerated from an initial angle of zero to a final angle of 6.3 rad by a rad counterclockwise angular acceleration of 2.0 s2 What is the angular velocity at 6.3 rad?
The final angular velocity of the carnival ride at a displacement of 6.3 rad is 25.2 rad/s.
Final angular velocity of the carnival ride
The final angular velocity of the carnival ride is determined by applying third kinematic equation as shown below;
ωf = ωi + 2αθ
where;
ωf is the final angular velocity of the carnival ride = ?ωi is the initial angular velocity of the carnival ride = 0α is the angular acceleration = 2.0 rad/s²θ is the angular displacement of the carnival ride = 6.3 radωf = 0 + 2(2.0) x 6.3
ωf = 25.2 rad/s
Thus, the final angular velocity of the carnival ride at a displacement of 6.3 rad is 25.2 rad/s.
Learn more about angular velocity here: https://brainly.com/question/6860269
Answer: 5.0 rad/s
Explanation: Because that’s what khan said so try it out.
An object was thrown from rest upward with an initial velocity of 10m/s with time frame of 6s find the distance of the object from it's resting point
Answer:
60
Explanation:
Work Done= Force×Displacement in the direction of the force
W.D. = 10×6
W.D. = 10×0.6
W.D. = 6m
A vertical straight conductor X of length 0.5m is held along the positive X-axis and situated in a uniform horizontal magnetic field of 0.1T which is pointing towards the positive Y-axis. (i) Calculate the magnitude and direction of force on X, when a current of 4A is passed through it. (ii) Through what angle must X be turned in a vertical plane so that the force on X is halved
Answer:
i. 0.2 N ii. 30°
Explanation:
(i) Calculate the magnitude and direction of force on X, when a current of 4A is passed through it.
The magnetic force F = BILsinФ where B = magnetic field strength = 0.1 T, I = current = 4 A and L= length of conductor = 0.5 m. Since the conductor X of length 0.5m is held along the positive X-axis and situated in a uniform horizontal magnetic field of 0.1T which is pointing towards the positive Y-axis, both B and L are perpendicular to each other. So, Ф = 90°
So, F = BILsinФ
F = 0.1 T × 4 A ×0.5 m × sin90°
F = 0.1 T × 4 A ×0.5 m × 1
F = 0.2 N
(ii) Through what angle must X be turned in a vertical plane so that the force on X is halved
If F' = BILsinФ' where Ф'=the new angle, and BIL = F
F'/F = sinФ'
Since F'/F = 1/2
sinФ' = 1/2
Ф' = sin⁻¹(1/2) = 30°
Red light of wavelength 630 nm passes through two slits and then onto a screen that is 1.3 m from the slits. The center of the 3rd order bright band on the screen is separated from the central maximum by 0.90 cm. a) What is the frequency of the light, the slit separation, and the angle of the 3rd order bright band
Answer:
a) f = 4.76 10¹⁴ Hz, b) d = 2.73 10⁻⁴ m, c) θ = 6.923 10⁻³ rad
Explanation:
a) In this problem the frequency of light is asked, let's use the relationship between the speed of the wave, its wavelength and its frequency
c = λ f
f = c /λ
f = [tex]\frac{3 \ 10^8}{630 \ 10^{-9}}[/tex]
f = 4.76 10¹⁴ Hz
b) slit separation (d)
the expression for the constructive interference of the double-slit experiment is
d sin θ = m λ
let's use trigonometry
tan θ = y / L
tan θ = [tex]\frac{sin \theta}{cos \theta}[/tex]
in general the angles are small, so we can approximate
tan θ = sin θ
tan θ = y/L
we substitute
d y / L = m λ
d = m L λ / y
we calculate
d = 3 1.3 630 10⁻⁹ /0.90 10⁻²
d = 2.73 10⁻⁴ m
c) the angle
tan θ = y / L
θ = tan⁻¹ y / L
θ = tan⁻¹ 0.9 10⁻² / 1.3
θ = tan⁻¹ 6,923 10⁻³
let's find the angle in radians
θ = 6.923 10⁻³ rad