Answer:
south of east
Explanation:
= 3 m/s
= north of east
= 6 m/s
= south of east = north of east
x and y component of
x and y component of
Magnitude
Direction
The magnitude of the change in velocity vector is and the direction is south of east.
Complete question is: While running, a person dissipates about 0.60 J of mechanical energy per step per kilogram of body mass. If a 60-kg person develops a power of 70 W during a race, how fast is the person running? (Assume a running step is 1.5 m long).
Answer: The person running at a speed of 2.91 m/s.
Explanation:
Given: Mass of runner = 60 kg
Runner dissipates = 0.6 J/kg per step
Average power = 70 W
1 step = 1.50 m
Energy dissipated by the runner is as follows.
Formula used to calculate the value of one step 'S' is as follows.
It is known that average velocity is equal to the total distance divided by time interval.
So, total distance for the given situation is as follows.
Hence, speed of the person is calculated as follows.
Thus, we can conclude that the person running at a speed of 2.91 m/s.
1. B. T
The period of a simple pendulum is given by:
(1)
where
L is the length of the pendulum
g is the gravitational acceleration
From the formula, we notice that the period of the pendulum does not depend on the mass of the bob. Therefore, when the bob's mass is doubled, the period does not change.
2. C: sqrt(6)*T
In this case, the pendulum is brought to the moon, where the gravitational acceleration is
If we substitute this value into the equation for the period (1), we find the new period of the pendulum:
3. B: It will no longer oscillate because there is no gravity in space
Explanation:
The motion (oscillation) of the pendulum is caused by the force of gravity, which "pulls" the bob towards the equilibrium position. If there is no gravity, then there is no force acting on the bob, therefore the pendulum can no longer oscillate.
So, the correct answer is
B: It will no longer oscillate because there is no gravity in space
Answer:
2. B
3. A
4. C
5. B
6. A
Explanation:
2. Sound waves use vibrating molecules to move. With this being said, sound waves would travel best through dense materials, and would travel worst in empty materials, like space. Using this information, you can infer that B would be the answer because water is denser than air and water is the densest material on that list.
3. The speed of the wave is equal to the frequency times the wavelength. Since it has a wavelength of 100 meter and 20 Hertz, the speed would 2000 m/s
4. Like noted in question 2, sound waves travel best in dense materials. Rock is the densest material in that last.
5. By looking at the chart, you can see that the speed increases by 4 m/s when the temperature increases by 10. Using simple division, you could determine that the speed would go up by 2 m/s since the jump between 15 degrees and 20 degrees is 5, which is half of 10, making the speed half of 4.
6. The speed would decrease because, like stated above, sound travels best through dense materials. Since rock is denser than air, the speed would decrease as it leaves.
Answer:
A. Both waves carry energy and refract is the correct answer.
Explanation: