Answer:
P=9.58 W
Explanation:
According to Newton's second law, and assuming friction force as zero:

The acceleration is given by:

So the force exerted by the motor is:

The work done by the motor is given by:


And finally, the power is given by:

Answer: 2940 J
Explanation: solution attached:
PE= mgh
Substitute the values:
PE= 10kg x 9.8 m/s² x 30 m
= 2940 J
<span>The statement is TRUE. Water does have potential energy at the top of a slope. The reason why is that potential energy is energy possessed by a body based on its position relative to a zero point. In this case, water at the top of the slope is at an elevation above ground (zero point). The energy is not kinetic (moving) energy since the water is not moving.</span>
Answer:
Same frequency, shorter wavelength
Explanation:
The speed of a wave is given by


where,
f = Frequency
= Wavelength
It can be seen that the wavelength is directly proportional to the velocity.
Here the frequency of the sound does not change.
But the velocity of the sound in air is slower.
Hence, the frequency remains same and the wavelength shortens.