Answer:
a) 567J
b) 283.5J
c)850.5J
Explanation:
The expression for the translational kinetic energy is,

Substitute,
14kg for m
9m/s for v

The translational kinetic energy of the center of mass is 567J
(B)
The expression for the rotational kinetic energy is,

The expression for the moment of inertia of the cylinder is,

The expression for angular velocity is,

substitute
1/2mr² for I
and vr for w
in equation for rotational kinetic energy as follows:



The rotational kinetic energy of the center of mass is 283.5J
(c)
The expression for the total energy is,

substitute 567J for E(r) and 283.5J for E(R)

The total energy of the cylinder is 850.5J
Answer:
He needs 1.53 seconds to stop the car.
Explanation:
Let the mass of the car is 1500 kg
Speed of the car, v = 20.5 m/s
He will not push the car with a force greater than, 
The impulse delivered to the object is given by the change in momentum as :

So, he needs 1.53 seconds to stop the car. Hence, this is the required solution.
Answer:
Explanation:
still water speed is 50 m / 25.0 s = 2.00 m/s or 200 cm/s
In lane 1 the effective speed would be 201.2 cm/s
5000 cm / 201.2 cm/s = 24.85 s
The change is 25.00 - 24.85 = 0.15 s decrease in time
In lane 8, the effective speed would be 198.8 cm/s
5000 cm / 198.8 cm/s = 25.15 s
The change is 25.00 - 25.15 = 0.15 s increase in time