Collision. Work. Power. Question 1

Question. Source. Yahoo ! Answers !

Issacs car collides with a stationary trolley . After the collision, the car and trolley lock together and move as one.mass of Issac’s car = 1700 kg
mass of trolley = 800 kg
Initial velocity of Issac’s car = 30 m s–11- Calculate the final velocity of the car and trolley together.
2- Mike’s car has a long crumple zone. Explain in detail why having this crumple zone would make a difference during impact. what are the ideas of velocity before and after the impact.

Issac’s car is towed away by a tow truck. The rope attached to the car makes an angle of 50 with the horizontal. The rope pulls the car with a force of 900N. The car moves a distance of 40 m along the horizontal road during a time of 20s.

3- What is the work done by the tow truck on the car.
4- What is the power produced by the tow truck while it is moving the car.

Solution.
1)
It is Perfectly inelastic collision .
M1*V1=(M1+M2)*UM1 – mass of Issac’s car
V1 – Initial velocity of Issac’s car
M2 – mass of trolley
U – final velocity of the car and trolley together1700*30=(1700+800)*U So, U = 20.4 m/s

2) than zone longer, Mike’s car safety

3)
W=F*D*COS (A)
W – work
F – force
D- distance
A – angle
W=900*40*COS(50)=23140.35 J

4)
P=W/t
P – Power
t – time
P=23140.35/20=1157.02 Watt