Answer:
B. A car of mass 2000 kg with speed 7 m/s
Explanation:
The kinetic energy of an object is given by:

where m is the mass of the object and v is its speed.
From the formula, we see that the larger the mass and the speed of the object, the larger its kinetic energy. Among the choices given, we see that the car with largest mass and largest speed is car B, which has a mass of 2000 kg and speed of 7 m/s. Its kinetic energy is:

We can verify that the other cars have smaller kinetic energy. In fact:
- Car A: 
- Car C: 
- Car D: 
So, car B is the one which has most kinetic energy.
Yes, I believe it will put points on your license. I think in some cases you will get your license revoked
Answer:
(a)10.5 rad/s2
(b) 20.9 rev
(c) 47.27 m
Explanation:
As the block of mass 53 kg is falling and pulling on the rope. The tension force on the rope must be equal to the gravity acting on the block according to Newton's 3rd law
T = mg = 53*9.81 = 519.93 N
Since this tension force would rotate the cylinder freely without any friction. The torque created by this tension force is
To = TR = 519.93 * 0.36 = 187.17 Nm
This solid cylinder would have a moment of inertia around it's rotating axis of:

(a)We can use Newton's 2nd law to calculate the angular acceleration exerted by such torque on the solid cylinder

(b) With such constant angular acceleration, the angle it would make after 5s is

Since each revolution equals to
of angle, we can calculate the number of revolution it makes

(c) Assume the thickness of the rope is negligible (and its wounded radius is unchanging), we can calculate the rope length unwinded after rotating 131.3rad

<span>BSL Physics Glossary - air resistance - definition. Translation: Air resistance is a force that is caused by air. The force acts in the opposite direction to an object moving through the air.</span><span>
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