How Do You Solve Basic Impulse-Momentum Physics Problems?

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The discussion focuses on solving basic impulse-momentum physics problems involving a bullet, a baseball, and a ball rebounding off a wall. Key calculations include determining the acceleration, force, time of acceleration, and impulse for the bullet as it penetrates a block. For the baseball, the change in momentum and average force applied by the bat are explored, while the ball's interaction with the wall involves calculating impulse and average force during impact. Participants express confusion about applying formulas and relationships between initial and final velocities, prompting requests for clarification on the principles of momentum and work done. The urgency of needing solutions within a short timeframe adds to the discussion's intensity.
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1. A bullet with a mass of 0.0050kg and moving with a speed of 400 m/s penetrates a distance of 0.08m into a wooden block firmly attached to the earth. Assume that the force that stops it is constant.

Compute for:
a) The acceleration of the bullet
b) The accelerating force
c) The time of the acceleration
d) The impulse of the force

2. A baseball has a mass of 0.200kg.
a) If the velocity of a pitched ball has a magnitude of 35m/s in the opposite direction, find the change in momentum of the ball and the impulse applied to it by the bat.
b) If the ball remains in contact with the bat for 2.0x10^-3 sec, find the average force applied by the bat.

3.) A ball with a mass of 0.40kg is thrown against a brick wall. It hits the wall moving horizontally to the left at 30m/s and it rebounds horizontally to the right at 20 m/s. Find the impulse of the force exerted on the ball by the wall. If the during the impact for 0.010sec, find the average force on the ball during the impact.





F = ma
a = v2-v1/t2-t1




I really don't have an idea how to solve this problems. Please help me. :cry:
 
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What is the relation between the initial velocity, final velocity and the dispalcemect?
What is the work done by the bullet on the wooden block?
what is the formula for momentum?
 
rl.bhat said:
What is the relation between the initial velocity, final velocity and the dispalcemect?
What is the work done by the bullet on the wooden block?
what is the formula for momentum?

1. I really don't know
2. It is not given
3. The formula for momentum is p = mv..
 
1. v^2 -u^2 = 2as
2.Work done by the bullet = F*s = loss of kinetic energy of the bullet = 1/2mv^2
 
rl.bhat said:
1. v^2 -u^2 = 2as
2.Work done by the bullet = F*s = loss of kinetic energy of the bullet = 1/2mv^2

v^2-u^2=2as?? I can't apply it since I don't have initial and final velocity.. OMG! please somebody help. I need this in three hours.
 
Last edited:
Initial velocity of the bullet is 400m/s. Finally it stops in the block. So the final velocity =0. s = 0.08 m.
 
Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
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