Question

2 A car with inertia 1200kg is driving through a parking lot. A wheeled platform of inertia 1800kg has just been unloaded from a flatbed truck. It gets away from them and is moving toward the car at a velocity of +2.5 m/s . The car cannot avoid it, and the two

Answer 1

1st law - law of inertia. An object at rest will tend to remain at rest and an object in motion will tend to remain in motion with constant speed if there is no net force acting upon it.

2nd law - F = ma. The force applied on an object by another object is proportional to the mass and acceleration.

3rd law - Any action force always has an equal and opposite reaction force.

The cars would continue to be at rest or in motion with constant speed if no net forces were acting up on them (i.e. the crash, friction). Since the force applied in the crash is proportional to the mass of the impacting car(s), the greater the mass of the impacting car(s), the greater the force applied, and therefore the greater the destruction. The smaller the mass of the impacting car(s), the less force is applied, and the destruction would be less. When the impacting car collided with the other car and applied a force, the car that was smashed into applied a reaction force with equal magnitude back onto the impacting car. Because a force is being applied to both the impacting car and the recieving car, both cars take damage.

Part B

Delta U= q + w
where:
delta U means change in internal energy
q is heat
w is work
In this problem,
q= 196 KJ ( its positive because the system absorbs energy)
w= 117 KJ (its positive because work is done on the system)

then,
delta U= 196 KJ + 117 KJ
delta U= 313 KJ