Homework Help: Physics

Posted by SARAH on Monday, February 7, 2011 at 3:04am.

Read each statement below. For each situation, calculate vi, vf, pi, pf, the impulse vector F􏰁t, and the amount of force needed for the change to occur. All situations refer to a truck with a mass of 2840 kg.
1. The truck has a velocity of 8.30 m/s and comes to a stop in 15.0 s.
2. The truck, initially at rest, reaches a velocity of 8.30 m/s in 20.0 s.
3. The truck is at rest. In 5.00 s, the truck backs up to a speed of 1.38 m/s.
4. The truck is moving backward with a velocity of 1.38 m/s and comes to a stop in 5.00 s.

Physics - drwls, Monday, February 7, 2011 at 5:54am
I'll do one of these. I don't see wht you can't do the others yourself. Give is a try.

1. The truck has a velocity of 8.30 m/s and comes to a stop in 15.0 s.
vi (inital) = 8.30 m/s
vf (final) = 0
pi (inital momentum) = 2840*8.3 = 23,572 kg*m/s
pf = 0
Impulse = pf - pi = -23672 kg*m/s
Force required = (impluse/time) =
-23672/15 = -1571 newtons
It is negative becasue the force must oppose the motion.
Physics - Anonymous, Monday, March 5, 2012 at 4:38pm
-1571 n

Answer this Question

Related Questions

Physics - Read each statement below. For each situation, calculate vi, vf, pi, ...
physics - A cart of mass m = 0.84 kg on a track undergoes a collision with ...
physics - A cart of mass m = 0.84 kg on a track undergoes a collision with ...
Physics - A 50g mass (M1) will be attached to the trolley M2) and will cause it ...
physics - calculate the friction force of an object? if weight=19600,vi=30ms-1,...
physics - 1 - By algebraic manipulation of the first two kinematic equations for...
Physics 2 (URGENT) - Which of the following has an acceleration in the same ...
PHYSICS PLEASE HELP QUICK - An object with an initial speed of 4.0 meters per ...
Physics/Science - A startled armadillo leaps upward rising 0.547 m in the first ...
Physics - 1. While riding on an elevator descending with a constant speed of 1.5...

For Further Reading

First Name:
School Subject:
Answer: