Presentation is loading. Please wait.

Presentation is loading. Please wait.

The cart’s change of momentum Δpx is

Published byVerawati Irawan Modified over 5 years ago

Similar presentations

Presentation on theme: "The cart’s change of momentum Δpx is"— Presentation transcript:

1

2 The cart’s change of momentum Δpx is
QuickCheck 11.1 The cart’s change of momentum Δpx is –20 kg m/s –10 kg m/s 0 kg m/s 10 kg m/s 30 kg m/s 2

3 The cart’s change of momentum Δpx is
QuickCheck 11.1 The cart’s change of momentum Δpx is –20 kg m/s –10 kg m/s 0 kg m/s 10 kg m/s 30 kg m/s Δpx = 10 kg m/s – (–20 kg m/s) = 30 kg m/s Negative initial momentum because motion is to the left and vx < 0. 3

4 QuickCheck 11.2 A 2.0 kg object moving to the right with speed 0.50 m/s experiences the force shown. What are the object’s speed and direction after the force ends? 0.50 m/s left At rest 0.50 m/s right 1.0 m/s right 2.0 m/s right 4

5 QuickCheck 11.2 A 2.0 kg object moving to the right with speed 0.50 m/s experiences the force shown. What are the object’s speed and direction after the force ends? 0.50 m/s left At rest 0.50 m/s right 1.0 m/s right 2.0 m/s right Δpx = Jx or pfx = pix + Jx 5

6 QuickCheck 11.3 A 2.0 kg object moving to the right with speed 0.50 m/s experiences the force shown. What are the object’s speed and direction after the force ends? 0.50 m/s left At rest 0.50 m/s right 1.0 m/s right 2.0 m/s right 6

7 QuickCheck 11.3 A 2.0 kg object moving to the right with speed 0.50 m/s experiences the force shown. What are the object’s speed and direction after the force ends? 0.50 m/s left At rest 0.50 m/s right 1.0 m/s right 2.0 m/s right 7

8 QuickCheck 11.4 A force pushes the cart for 1 s, starting from rest. To achieve the same speed with a force half as big, the force would need to push for s 1 s 2 s 4 s 1 4 1 2 8

9 QuickCheck 11.4 A force pushes the cart for 1 s, starting from rest. To achieve the same speed with a force half as big, the force would need to push for s 1 s 2 s 4 s 1 4 1 2 9

10 QuickCheck 11.5 A light plastic cart and a heavy steel cart are both pushed with the same force for 1.0 s, starting from rest. After the force is removed, the momentum of the light plastic cart is ________ that of the heavy steel cart. greater than equal to less than Can’t say. It depends on how big the force is. 10

11 QuickCheck 11.5 A light plastic cart and a heavy steel cart are both pushed with the same force for 1.0 s, starting from rest. After the force is removed, the momentum of the light plastic cart is ________ that of the heavy steel cart. greater than equal to less than Can’t say. It depends on how big the force is. Same force, same time → same impulse Same impulse → same change of momentum 11

12 QuickCheck 11.6 Two 1.0 kg stationary cue balls are struck by cue sticks. The cues exert the forces shown. Which ball has the greater final speed? Ball 1 Ball 2 Both balls have the same final speed. 12

13 QuickCheck 11.6 Two 1.0 kg stationary cue balls are struck by cue sticks. The cues exert the forces shown. Which ball has the greater final speed? Ball 1 Ball 2 Both balls have the same final speed. 13

14 QuickCheck 11.7 You awake in the night to find that your living room is on fire. Your one chance to save yourself is to throw something that will hit the back of your bedroom door and close it, giving you a few seconds to escape out the window. You happen to have both a sticky ball of clay and a super-bouncy Superball next to your bed, both the same size and same mass. You’ve only time to throw one. Which will it be? Your life depends on making the right choice! Throw the Superball. Throw the ball of clay. It doesn’t matter. Throw either. 14

15 QuickCheck 11.7 You awake in the night to find that your living room is on fire. Your one chance to save yourself is to throw something that will hit the back of your bedroom door and close it, giving you a few seconds to escape out the window. You happen to have both a sticky ball of clay and a super-bouncy Superball next to your bed, both the same size and same mass. You’ve only time to throw one. Which will it be? Your life depends on making the right choice! Throw the Superball. Throw the ball of clay. It doesn’t matter. Throw either. Larger Δp → more impulse to door 15

16 QuickCheck 11.8 A mosquito and a truck have a head-on collision. Splat! Which has a larger change of momentum? The mosquito The truck They have the same change of momentum. Can’t say without knowing their initial velocities. 16

17 QuickCheck 11.8 A mosquito and a truck have a head-on collision. Splat! Which has a larger change of momentum? The mosquito. The truck. They have the same change of momentum. Can’t say without knowing their initial velocities. Momentum is conserved, so Δpmosquito + Δptruck = 0. Equal magnitude (but opposite sign) changes in momentum. 17

18 QuickCheck 11.9 The 1 kg box is sliding along a frictionless surface. It collides with and sticks to the 2 kg box. Afterward, the speed of the two boxes is 0 m/s 1 m/s 2 m/s 3 m/s There’s not enough information to tell. 18

19 QuickCheck 11.9 The 1 kg box is sliding along a frictionless surface. It collides with and sticks to the 2 kg box. Afterward, the speed of the two boxes is 0 m/s 1 m/s 2 m/s 3 m/s There’s not enough information to tell. 19

20 QuickCheck 11.10 The two boxes are sliding along a frictionless surface. They collide and stick together. Afterward, the velocity of the two boxes is 2 m/s to the left. 1 m/s to the left. 0 m/s, at rest. 1 m/s to the right. 2 m/s to the right. 20

21 QuickCheck 11.10 The two boxes are sliding along a frictionless surface. They collide and stick together. Afterward, the velocity of the two boxes is 2 m/s to the left. 1 m/s to the left. 0 m/s, at rest. 1 m/s to the right. 2 m/s to the right. 21

22 QuickCheck 11.11 The two boxes are on a frictionless surface. They had been sitting together at rest, but an explosion between them has just pushed them apart. How fast is the 2 kg box going? 1 m/s 2 m/s 4 m/s 8 m/s There’s not enough information to tell. 22

23 QuickCheck 11.11 The two boxes are on a frictionless surface. They had been sitting together at rest, but an explosion between them has just pushed them apart. How fast is the 2 kg box going? 1 m/s 2 m/s 4 m/s 8 m/s There’s not enough information to tell. 23

24 QuickCheck 11.12 A cart is rolling at 5 m/s. A heavy lead weight is suspended by a thread beneath the cart. Suddenly the thread breaks and the weight falls. Immediately afterward, the speed of the cart is Less than 5 m/s Still 5 m/s More than 5 m/s 24

25 QuickCheck 11.12 A cart is rolling at 5 m/s. A heavy lead weight is suspended by a thread beneath the cart. Suddenly the thread breaks and the weight falls. Immediately afterward, the speed of the cart is Less than 5 m/s Still 5 m/s More than 5 m/s No external forces to exert an impulse. The falling weight still has forward momentum. 25

Download ppt "The cart’s change of momentum Δpx is"

Similar presentations

Chapter 9 Impulse and Momentum

Chapter 9 Impulse and Momentum
Forces.

Forces.
Aim: How can we apply conservation of momentum to collisions? Aim: How can we apply conservation of momentum to collisions? Identify conservation laws.

Aim: How can we apply conservation of momentum to collisions? Aim: How can we apply conservation of momentum to collisions? Identify conservation laws.
Physics 1100 - Spring 2012 Chapter 6 - Momentum Momentum Impulse Impulse Changes Momentum Bouncing Conservation of Momentum Collisions More Complicated.

Physics Spring 2012 Chapter 6 - Momentum Momentum Impulse Impulse Changes Momentum Bouncing Conservation of Momentum Collisions More Complicated.
Collisions (L8) collisions can be very complicated two objects bang into each other and exert strong forces over short time intervals fortunately, even.

Collisions (L8) collisions can be very complicated two objects bang into each other and exert strong forces over short time intervals fortunately, even.
© 2015 Pearson Education, Inc.

© 2015 Pearson Education, Inc.
Journal 1/27/15 Momentum is the basic idea behind weapons like guns. What kind of defensive thing might we create using momentum or collisions? Objective.

Journal 1/27/15 Momentum is the basic idea behind weapons like guns. What kind of defensive thing might we create using momentum or collisions? Objective.
Problem of the Day An 1800 kg car stopped at a traffic light is struck from the rear by a 900 kg car, and the two become entangled, moving along the same.

Problem of the Day An 1800 kg car stopped at a traffic light is struck from the rear by a 900 kg car, and the two become entangled, moving along the same.
Conservation of Momentum

Conservation of Momentum
L-8 (I) Physics of Collisions (II) Work and Energy I. Collisions can be very complicated –two objects bang into each other and exert strong forces over.

L-8 (I) Physics of Collisions (II) Work and Energy I. Collisions can be very complicated –two objects bang into each other and exert strong forces over.
Momentum and Energy in Collisions. A 2kg car moving at 10m/s strikes a 2kg car at rest. They stick together and move to the right at ___________m/s.

Momentum and Energy in Collisions. A 2kg car moving at 10m/s strikes a 2kg car at rest. They stick together and move to the right at ___________m/s.
ConcepTest Clicker Questions College Physics, 7th Edition

ConcepTest Clicker Questions College Physics, 7th Edition
1. ConcepTest 7.1Rolling in the Rain 1. ConcepTest 7.1 Rolling in the Rain 1) speeds up 2) maintains constant speed 3) slows down 4) stops immediately.

1. ConcepTest 7.1Rolling in the Rain 1. ConcepTest 7.1 Rolling in the Rain 1) speeds up 2) maintains constant speed 3) slows down 4) stops immediately.
Conceptual MC Questions

Conceptual MC Questions
A. Rolling in the Rain An open cart rolls along a frictionless track while it is raining. As it rolls, what happens to the speed of the cart as the rain.

A. Rolling in the Rain An open cart rolls along a frictionless track while it is raining. As it rolls, what happens to the speed of the cart as the rain.
AP Physics Review Ch 7 – Impulse and Momentum

AP Physics Review Ch 7 – Impulse and Momentum
Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Impulse Momentum The impulse-momentum theorem Conservation of momentum.

Copyright © 2007, Pearson Education, Inc., Publishing as Pearson Addison-Wesley. Impulse Momentum The impulse-momentum theorem Conservation of momentum.
Fri. Feb. 25th1 PHSX213 class Class stuff –Questions ? Conservation of Linear Momentum Collision terminology Collisions.

Fri. Feb. 25th1 PHSX213 class Class stuff –Questions ? Conservation of Linear Momentum Collision terminology Collisions.
Collision Lab and conservation of momentum This “conservation” law is one of the biggest ideas in physics and motion.

Collision Lab and conservation of momentum This “conservation” law is one of the biggest ideas in physics and motion.
Principles of Physics. - property of an object related to its mass and velocity. - “mass in motion” or “inertia in motion” p = momentum (vector) p = mvm.

Principles of Physics. - property of an object related to its mass and velocity. - “mass in motion” or “inertia in motion” p = momentum (vector) p = mvm.

Similar presentations

Ads by Google