Answer B is the correct answer
We know that kinetic energy , where m is the mass of object and v is the velocity of object.
In this case only velocity is the variable, mass remains constant.
So point having higher velocity has higher kinetic energy.
When it leaves the racket, the ball will be having a certain height, but just before it reaches the ground it will not having any height. So maximum velocity of ball is at that time when it reaches just above the ground.
So option B is the correct answer.
Answer:
a)
b) Efficiency=76.77%
Explanation:
a)
In order to solve this problem, we can use the following formula:
the problem provides us with all the necessary information so we can directly use the formula:
b) In order to find the efficiency, we can use the following formula:
so we get:
Efficiency=76.77%
Answer:
v = 8.4 m/s
Explanation:
The question ays, "A longitudinal wave has a frequency of 200 Hz and a wavelength of 4.2m. What is the speed of the wave?".
Frequency of a wave, f = 200 Hz
Wavelength = 4.2 cm = 0.042 m
We need to find the speed of the wave. The formula for the speed of a wave is given by :
So, the speed of the wave is equal to 8.4 m/s.