Answer:
The time between the emission of the wave and it's reception was 0.4 seconds.
Explanation:
The sound wave emitted by the sonar traveled from the boat to the fishes and came back, therefore the distance of it's total route is twice the distance from the boat to the fishes. We can apply the average speed formula in order to solve this problem, this is done below:
[tex]\text{speed} = \frac{\text{distance}}{\text{time}}[/tex]
We were given the distance traveled by the wave and it's speed, therefore we can solve for the time:
[tex]\text{time} = \frac{\text{distance}}{\text{speed}}\\\\\text{time} = \frac{(2*300)}{1500}\\\\\text{time} = \frac{600}{1500} = 0.4 \text{ s}[/tex]
The time between the emission of the wave and it's reception was 0.4 seconds.
PLEASE HELP!!!!!
When describing image formation for plane mirrors, what is an important rule
to remember about light rays?
Answer: The image formed by a plane mirror is always virtual (meaning that the light rays do not come from the image), upright and of the same shape and size as the object it is reflecting.
Answer: B. The angle when it leaves is the same as the angle when it hits
Explanation:
Apex
A non-uniform rod 60cm long and weighs 32N is balanced at the 45cm mark. A load of 2N is hung on the zinc rod at the 25cm mark. Where must a second knife-edge be placed to balance the zinc rod horizontally
Answer:
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
Explanation:
From the law of equilibrium, ΣF = 0 and ΣM = 0.
Let R be the reaction at the knife edge. Since the weight of the rod and zinc load act downward, and we take downward position as negative
-32 N - 2 N + R = 0
-34 N = -R
R = 34 N
Also, let us assume the knife-edge is x cm from the zero mark. Taking moments about the weight and assuming the knife-edge is right of the weight of the rod. Taking clockwise moments as positive and anti-clockwise moments as negative,
-(45 - 25)2 + (x - 45)R = 0
-(20)2 + (x - 45)34 = 0
-40 = -(x - 45)34
x - 45 = 40/34
x - 45 = 1.18
x = 45 + 1.18
x = 46.18 cm
x ≅ 46.2 cm
The second knife-edge must be placed 46.2 cm from the zero mark of the rod.
When salt is added to the water what happens to the surface?
Answer:
it increases the surface tension of the water
Which force does not operate at a distance of 1 m?
A. Weak nuclear
O B. Electric
C. Gravitational
D. Magnetic
Answer:
A
Explanation:
a 50.0kg bicyclist on a 10.0kg bicycle speeds up from a 5.00m/s to 10.0m/s
Answer:
The total kinetic energy before accelerating = 750 JThe total kinetic energy after accelerating = 3,000 JTotal work done = 2,250 JExplanation:
Given:
Mass of bicyclist = 50 kg
Mass of bicycle = 10 kg
Initial velocity (u) = 5 m/s
Final velocity (v) = 10 m/s
Find:
(a) What was the total kinetic energy before accelerating = ?
(b) What was the total kinetic energy after accelerating = ?
(c) How much work was done to increase the kinetic energy of the bicyclist = ?
Computation:
Total mass (M) = 50 kg + 10 kg = 60 kg
1. The total kinetic energy before accelerating = 1/2[Mu²]
The total kinetic energy before accelerating = 0.5[(60)(5)²]
The total kinetic energy before accelerating = 750 J
2. The total kinetic energy after accelerating = 1/2[Mv²]
The total kinetic energy after accelerating = 0.5[(60)(10)²]
The total kinetic energy after accelerating = 3,000 J
3. Total work done = Δ K.E
Total work done = 3,000 J - 750 J
Total work done = 2,250 J
state the principle of conservation of energy
Answer:
Principal of Conservation of Energy states that " Energy is neither created nor destroyed. However, It is just converted to other forms of energy"
A 4.0 kg block is initially at rest on a frictionless, horizontal surface. The block is moved 8.0 m by the application of a constant 10.0 N horizontal force. If the block slides into a fixed horizontal spring and comes to rest when the spring is compressed a distance of x=0.25m. Determine the spring constant of the fixed horizontal spring. Show all formula with substitutions and units.
Answer:
k = 2560 N/m
Explanation:
To find the spring constant, you take into account that all the kinetic energy of the block becomes elastic potential energy in the spring, when the block compressed totally the spring:
[tex]K=U\\\\\frac{1}{2}mv^2=\frac{1}{2}kx^2[/tex]
m: mass of the block = 4.0kg
v: velocity of the block just before it hits the spring
x: compression of the spring = 0.25m
k: spring constant = ?
You solve the previous equation for k:
[tex]k=\frac{mv^2}{x^2}[/tex] (1)
Then, you have to calculate the velocity v of the block. First, you calculate the acceleration of the block by using the second Newton law:
[tex]F=ma[/tex]
F: force over the block = 10.0N
a: acceleration
[tex]a=\frac{F}{m}=\frac{10.0N}{4.0kg}=2.5\frac{m}{s^2}[/tex]
With this value of a you can calculate the final velocity after teh block has traveled a distance of 8.0m:
[tex]v^2=v_o^2+2ad[/tex]
vo: initial velocity = 0m/s
d: distance = 8.0m
[tex]v=\sqrt{2ad}=\sqrt{2(2.5m/s^2)(8.0m)}=6.32\frac{m}{s}[/tex]
Now, you can calculate the spring constant by using the equation (1):
[tex]k=\frac{mv^2}{x^2}=\frac{(4.0kg)(6.32m/s)^2}{(0.25m)^2}=2560\frac{N}{m}[/tex]
hence, the spring constant is 2560 N/m
A device has power -2 D . The device is
a.A convex lens of focal length 50 cm
b.A concave lens of focal length 50 cm
c.A convex lens of focal length 2 m
d.A concave lens of focal length 2 m
Answer:
b.
Explanation:
-vesign shows the lens is CONCAVE
f=1/power
!! i will mark as brainliest so pls answer quick !!
The student becomes negatively charged because of the friction between her socks and the carpet.
Explain why the friction causes the student to become charged
Answer:
A student becomes negatively charged because of the friction between his socks and the carpet. ... The electrons get rubbed and move towards the carpet so the carpets electrons move away and the student becomes negatively charged.
Please explain it’s in the photo
Answer:
Since air resistance actually stops vehicles and goes in a vector opposite to the direction of the vehicle and slows it down. Vehicles would want to make vehicles aerodynamic. Many cars bump into air molecules therefore making air resistance. Aerodynamic cars will lesser the allowance of bumping into said molecules. Thats why cars like to cut down on air resistance
Air resistance is friction.
-- Friction steals kinetic energy.
-- A car gets kinetic energy by burning gasoline, and uses the kinetic energy to get where it needs to go.
-- If anything steals the car's kinetic energy, then the car has to burn more gasoline to get where it needs to go.
-- Gasoline costs money.
-- Anything that steals a car's kinetic energy costs you more money to operate the car.
(Another thing that takes kinetic energy away from the car is the car's brakes. The driver uses the brakes when he WANTS to slow down or stop, so it's not stealing, but it still costs kinetic energy and money.)
Which objects would sink in honey, which has a density of 1.4 g/cm³? Check all that apply.
Answer:
any object that has density more than 1.4
Explanation:
The object that has density more than 1.4 is denser than the honey
state two factors that affect the turning effect of force
Answer:The first is the magnitude of the force applied on the body and the second is the perpendicular distance from the line of action of force and the axis of rotation of the body.
Explanation:
A car starts from rest and attains a velocity of 30m/s in 5 sec . calculate the total distance travel by that car and acceleration
Answer:
Acceleration (a) = 6 m/s²
Total distance travel by car(s) = 75 meter
Explanation:
Given:
Initial velocity (u) = 0
Final velocity (v) = 30 m/s
Time (t) = 5 sec
Find:
Total distance travel by car(s) = ?
Acceleration (a) = ?
Computation:
v = u +at
30 = 0 + a(5)
30 = a(5)
Acceleration (a) = 6 m/s²
Total distance travel by car(s) = ut +1/2(a)(t)²
Total distance travel by car(s) = 1/2(a)(t)²
Total distance travel by car(s) = (0.5)(6)(5)²
Total distance travel by car(s) = 75 meter
Describe The energy conversions that occur when coal is formed, and then burned to produce thermal energy.
Answer:
When energy contained in coal is turned into heat, and then into electrical energy. As boiling water heated by the burning coal is cooled, steam forges from these cone-shaped cooling towers.
Earth receives some of the Sun's energy in the form of heat and light.
What type of energy does heat and light from the Sun begin as?
O A) nuclear
OB) chemical
OC) electrical
OD) mechanical
Answer:
a) nuclear
Explanation:
what is brightness. help asap
Answer:
The subjective visual sensation related to the intensity of light emanating from a surface or from a point source.
A remote controlled plane accelerates to a velocity of 21.0 m/s while covering a distance of 87.4 m in 6.11 s. What was the plane's initial velocity?
Answer:
7.61 m/s
Explanation:
Given:
Δx = 87.4 m
v = 21.0 m/s
t = 6.11 s
Find: v₀
Δx = ½ (v + v₀) t
87.4 m = ½ (21.0 m/s + v₀) (6.11 s)
v₀ = 7.61 m/s
71.6
Δx = 87.4 m
v = 21.0 m/s
t = 6.11 s
Find: v₀
Δx = ½ (v + v₀) t
87.4 m = ½ (21.0 m/s + v₀) (6.11 s)
v₀ = 7.61 m/s
A 1.2 m steel rod moves through a uniform magnetic field of 0.020 T at 30 m/s. What emfis induced between the two ends of the steel rod?
0.36 V
0.50 V
0.60 V
0.72 V
Answer:
0.50v
Explanation:
Now EMF is induced when there is motion of a conductor in an electric field. Michael Faraday in the annals of scientific history discovered this.
This is expressed mathematically as;
E = Magnetic field / t
but t = d/ v; d- distance, v-velocity, time
Hence E = magnetic field/ d/v
= Magnetic field× v/ d
= 0.02×30/ 1.2= 0.5
In which space, outdoors or in your classroom, would it be easier to hear a musician? Explain
Answer:
It is easier to hear a musician in the classroom than outdoors
Explanation:
It is easier to hear a musician in the classroom due to the improved acoustics provided by the walls of the classroom whereby along with the direct sound of the musician, which is the lead source of the sounds, there is an increased number of indirect sound reaching the ear in the classroom than outdoors and due to precedence effect, all the sound appear to come from the musician
In music played outside, along side the direct sound from the musician, the indirect sound that reach the ear is echoed from maybe by only the ground while the majority of the sound from the music wanders away with the wind and in other directions as well as being absorbed such that speakers will be required to improve the sound of the music outdoors.
Isaac throws an apple straight down from a tree with an initial speed of 5.0 \dfrac{\text m}{\text s}5.0 s m 5, point, 0, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction. It hits the ground with a final speed of 12 \dfrac{\text m}{\text s}12 s m 12, start fraction, start text, m, end text, divided by, start text, s, end text, end fraction. How many seconds did the apple fall?
Answer:
0.71s
Explanation:
From Newton's law of motion ;
V =U +gt
V is the final velocity or speed
U is the initial velocity or speed
g is acceleration of free fall due to gravity given as 9.8m/S2
Note when a body moves horizontally down its said to do so with the aid of the force of gravity
Hence the final velocity is aided by gravity.
From the above formula;
t =V-U/ g
t= 12-5/ 9.8 = 0.71s
Answer: .71
Explanation:
Khan academy
You get in your car to drive to school at 7:33 am and drive 10 miles north at a constant speed until 7:45
am, when you realize you left your homework on the kitchen table. You turn around and drive 10 miles
south back to your house and retrieve your homework at 8:00 am. You get back in the car and drive 15
miles north to school at a constant speed arriving at school at 8:29 am sharp, just in time to make it
before the bell rings.
e
Answer:
5.) 16.8 m/s
6.) 16.1 mph
7.) Moving fast.
Explanation:
5.) From the question, the total time will be:
7:33 am to 7:45 am = 12 minutes
As the car turns around,
7 : 45 am to 8 : 00am = 15 minutes
As you get back in the car and drive 15
miles north to school at a constant speed arriving at school at 8:29 am
8:00am to 8:29 am = 29 minutes
Total time = 12 + 15 + 29 = 56 minutes
Convert the minutes to second by multiplying the result by 60
Total time = 56 × 60 = 3360 seconds
Total distance covered will be
10 miles + 10 miles + 15 miles = 35 miles
Convert mile to meter by multiplying the result by 1609.344
35 × 1609.344 = 56327.04
Speed is a scale quantity. It only involves magnitude but no direction.
Average speed = total distance/total time
Average speed = 56327.04/3360
Average speed = 16.764 m/s
6.) Velocity = displacement/time
Velocity is a vector quantity. We will consider both the magnitude and direction
Total displacement = 10 miles - 10 miles + 15 miles = 15 miles.
Total time = 56 minutes
Convert minutes to hours by dividing it by 60
Total time = 56/60 = 0.93 hours
Substitute the time and displacement into the formula
Velocity = 15/0.93 = 16.07 mph
7.) . If you looked at your speedometer on your drive to school and it read 30mph, this value describes you move with a fast speed.
An astronaut is moving in space when a big explosion occurs about 50 meters behind him. How will the astronaut come to know about the explosion?
Choose:--
From the sound of the explosion
From the light due to the explosion
From light and sound due to the explosion
From the vibrations due to the explosion
Answer:
The correct answer is B.
The astronaut will know due to the light from the explosion.
Explanation:
Sound and vibrations require a medium such as air to travel through. Space, there is no air. Only a vacuum. So sound and vibrations are unable to travel. Light requires no medium to travel. It can go through a vacuum.
Therefore the Astronaut will see a bright flash of light as it travels from the explosion to outer space. It is also important to note that light can travel very far because nothing else interacts with its wave particles and as such, it cannot be impeded.
Cheers!
How much power is used by 4 A appliance that is plugged into a 120 V circuit for 4 minutes
Answer:
Power, P = 480 W
Explanation:
It is required to find the power used by 4 A appliance that is plugged into a 120 V circuit for 4 minutes. Power used by an appliance is given by the formula as follows :
[tex]P=VI[/tex]
Plugging all the values we get :
[tex]P=120\times 4\\\\P=480\ W[/tex]
So, the power used by the appliance is 480 W.
Why did the Founding Fathers want to include a bill of rights in the U.S.
Constitution?
A. To ensure that the government couldn't take away the individual
rights of citizens
B. To provide future generations a way to amend, or change, the
Constitution
C. To allow states to write and approve their own state constitutions
D. To give state governments more power than the federal
government
Answer:
Its A
Explanation:
Thats because federalists wanted to take away rights. But the fathers wanted to definitely ensure that each person had equal rights and liberty.
Solar energy is a form of
energy from the Sun.
OA) heat
OB) nuclear
OC) mechanical
OD) electromagnetic
Answer:
Solar energy is a form of Electromagnetic energy
Explanation:
Solar energy is constantly flowing away from the sun and throughout the solar system. Solar energy warms the Earth, causes wind and weather, and sustains plant and animal life. The energy, heat, and light from the sun flow away in the form of electromagnetic radiation (EMR
A ramp is a simple machine called the
a. wedge
b. pulley
c. inclined plane
d. lever
Answer:
Inclined Plane is the answer
Answer:
Inclined plane
Explanation:
It is called Inclined plane since it is a flat surface at an angle.
50 COINS AMAZING PLEASE HELP ME!!!
Answer:
ok
Explanation:
Ok
Which statement best describes the long-term effects of using renewable resources?
A) There is an unlimited supply of fresh water on the Earth.
B) Melting glacier ice will supple more fresh water.
C) As populations decrease, renewable resources will also decrease.
D) As demand for renewable energy increase, fossil fuel use will decrease.
Answer:
The answer is D) As demand for renewable energy increase, fossil fuel use will decrease.
Explanation:
I just took the exam
The statement that best describes the long-term effects of using renewable resources is as follows:
As demand for renewable energy increases, fossil fuel use will decrease.Thus, the correct option for this question is D.
What is meant by Renewable resources?Renewable resources may be defined as those resources that cannot be exhausted and are capable in order to furnish a continuous source of clean energy. Examples include hydropower, geothermal power, wind energy, solar energy, etc.
The dependency on renewable resources reduces the demand for non-renewable resources like the combustion of fossil fuels that emit highly toxic constituents in the environment which are extremely harmful to living entities.
Therefore, as demand for renewable energy increases, fossil fuel use will decrease is the statement that best describes the long-term effects of using renewable resources. Thus, the correct option for this question is D.
To learn more about Renewable resources, refer to the link:
https://brainly.com/question/79953
#SPJ2
Ed biked home from school in 400 seconds. His home is located 2000 m south of the school. What was his velocity?
[tex]answer = 5 \: \: metre \: per \: second\\ distance = 2000 \: m \\ time = 400 \: seconds \\ velocity = \: \frac{distance \:t ravelled}{time \: taken} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = \frac{2000}{400} \\ \: \: \: \: \: \: \: \: \: = 5 \: metre \: per \: second \\ hope \: it \: helps[/tex]
which refers to a transfer of thermal energy between two objects?
A. potential energy
B. kinetic energy
C. heat
D. temperature