B. Fluid forces
C. Air resistance
D. Friction
gravity is the correct answer
27%
20%
15%
Answer:
The percentage of its mechanical energy does the ball lose with each bounce is 23 %
Explanation:
Given data,
The tennis ball is released from the height, h = 4 m
After the third bounce it reaches height, h' = 183 cm
= 1.83 m
The total mechanical energy of the ball is equal to its maximum P.E
E = mgh
= 4 mg
At height h', the P.E becomes
E' = mgh'
= 1.83 mg
The percentage of change in energy the ball retains to its original energy,
ΔE % = 45 %
The ball retains only the 45% of its original energy after 3 bounces.
Therefore, the energy retains in each bounce is
∛ (0.45) = 0.77
The ball retains only the 77% of its original energy.
The energy lost to the floor is,
E = 100 - 77
= 23 %
Hence, the percentage of its mechanical energy does the ball lose with each bounce is 23 %
Answer: 23
Explanation: gradpoint
Answer:
No
Explanation:
It is an example of experimental group. Experimental group is defined as the group in an experiment under which each variable is tested, however, one variable is tested at a time.
On the other hand, control group is defined as the group which does not receive treatment by the researchers.
The only difference between the both group is that, under experimental group independent variable is changed but under control group it is held constant.
Answer:
false
Explanation:
The forehand stroke is a basic shot in tennis, variations are allowed in order to boost performance (power, topspin and accuracy) of the player. Some guidelines to choose the correct forehand stroke are to visualize the correct stroke, position correctly, correct footwork and selecting shot location.