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S-EPHY001 -CEE 11(TO4)-2nd SEM SY 2021-2022 - https://dlsud.edu20.org/student_lesson/show/3289675?lesson_id=154155…
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S-EPHY001 -CEE 11(TO4)-2nd SEM SY 2021-2022
Module 4. IMPULSE and MOMENTUM
Sample Problems - Momentum
Immersive Reader
Problem 1. A soccer ball of mass 420 g is kicked at 20 m·s−1 towards the goal post. Calculate the momentum of the ball.
Given:
m= 420 g = 0.420 kg
v = 20 m/s
Required: p
Solution: p= mv = 0.420 kg (20 m/s) = 8.4 kg•m/s or N•s
Problem 2. Two billiard balls roll towards each other. They each have a mass of 0.3 kg. Ball 1 is moving at v1 = 1m · s−1 to the right,
while ball 2 is moving at v2 = 0.8m · s−1 to the left. Calculate the total momentum of the system.
Given:
m1=m2= 0.3 kg
v1 = 1 m/s to the right
v2 = 0.8 m/s to the left
Required: total momentum , p1 +p2
Solution:
ptotal= p1 + p2 = m1v1 + m2v2 = (0.3 kg)(1 m/s) +(0.3 kg)(-0.8 m/s) = 0.06 N•s to the right
Problem 3. a.) A 1000 - kg car travels at a speed of 20 m/s. At what speed must a 3000-kg truck travel to have the same momentum?
b.) At what speed must a 7.3 kg bowling ball travel to have the same momentum?
a. Given:
mcar = 1000 kg
mtruck = 3000 kg
vcar = 20 m/s
Required: vtruck
Solution: mcarvcar= mtruckvtruck
;
1000 kg(20 m/s) = 3000vtruck
vtruck = 6.67 m/s
b. mball = 7.3 kg , vball = ? at same momentum
20000 = 7.3 vball ; vball = 2739.73 m/s
Problem 4. Two vehicles are approaching an intersection. One is a 2500 kg truck traveling at 14 m/s from east to west (the -x
direction) and the other is a 1500 kg Sedan going south to north ( the + y direction) at 23 m/s.
a.) Find the x and y components of the net momentum of this system.
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b.)
S-EPHY001 -CEE 11(TO4)-2nd SEM SY 2021-2022 - https://dlsud.edu20.org/student_lesson/show/3289675?lesson_id=154155…
What are the magnitude and direction of the net momentum?
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