Answer:
F = 3.20 N
Explanation:
Given:
Work done by child = 80.2 j
Distance that the car moves = 25.0 m
We need to find the force acting on the car.
Solution:
Using work done formula as.
Where:
W = Work done by any object.
F = Force (push or pull)
d = distance that the object moves.
Substitute in work done formula.
F = 3.20 N
Therefore, force acting on the car F = 3.20 N
Answer:
Therefore letter <u>C is the correct answer.</u>
Explanation:
In a projectile motion the total time in the air can be calculated using the following equation:
We analyze the y-component motion.
When the final velocity (v(f)) is equal to zero we calculate the upward time and multiplying it by 2 we find the total time in the air. So we will have:
We can see that the <u>total time is directly proportional to the angle</u>, then when <u>θ increase t increase.</u>
Therefore letter C is the correct answer.
I hope it helps you!
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 %