Question

A cart is moving along a long, frictionless horizontal air track. Two students are pushing on...

A cart is moving along a long, frictionless horizontal air track. Two students are pushing on it:

Bob is doing positive work, and Alice is doing negative work If the cart is moving to the left and slowing down, which statement below is true?

A) Bob pushes to the right; the net work done on the cart is positive,

B) Bob pushes to the left; the net work done on the cart is positive

C) Bob pushes to the right: the net work done on the cart is negative

D) Bob pushes to the left; the net work done on the cart is negative

E)Bob pushes to the right; the net work done on the cart is zero.

0 0
Add a comment Improve this question Transcribed image text
Answer #1

The cart moves to left, the direction of velocity is to the left. It is given that the Bob is doing a positive work. So, the force applied by Bob is in the same direction as the displacement of the cart. The displacement of the cart is to the left, therefore the force applied by Bob will also be to the left.

By the work energy theorem we know that the net work done is equal to the change in kinetic energy of the system.

Since the object slows down the kinetic energy reduces, the final kinetic energy is less than the initial kinetic energy of the system. Therefore the net work done on the cart is negative.

Option (D) is correct.

Add a comment
Know the answer?
Add Answer to:
A cart is moving along a long, frictionless horizontal air track. Two students are pushing on...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • 5) Little Bobby is pushing a cart and the cart starts to slow down, which free...

    5) Little Bobby is pushing a cart and the cart starts to slow down, which free body diagram below is correct for the cart slowing down as Little Bobby continues to pushes. A) F FN F D) FN F applied F applied applied F applied 6) Bob applies a force with a magnitude of |F = 160 N to a box downward at an angle = 60° relative to the horizontal, the box has a weight of 196 N and...

  • A 0.151kg glider is moving to the right on a frictionless, horizontal air track with a...

    A 0.151kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.840m/s . It has a head-on collision with a 0.302kg glider that is moving to the left with a speed of 2.26m/s . Suppose the collision is elastic. Part A Find the magnitude of the final velocity of the 0.151kg glider. Part B Find the magnitude of the final velocity of the 0.302kg glider

  • 11) Bob is moving a 15 kg box along a horizontal floor, by pushing down on...

    11) Bob is moving a 15 kg box along a horizontal floor, by pushing down on the box at an angle = 30° below the horizontal with a force of F = 80 N and there is a frictional force of 50 N acting on the box as he pushes. What is the horizontal acceleration of the box? box 12) Using the same information in the above problem, Bob is moving a 15 kg box along a horizontal floor, by...

  • A cart of mass 260 g is placed on a frictionless horizontal air track. A spring...

    A cart of mass 260 g is placed on a frictionless horizontal air track. A spring having a spring constant of 8.0 N/m is attached between the cart and the left end of the track. The cart is displaced 3.5 cm from its equilibrium position. (a) Find the period at which it oscillates.    s (b) Find its maximum speed.    m/s (c) Find its speed when it is located 2.0 cm from its equilibrium position.   m/s

  • A 0.150 kg glider is moving to the right on a frictionless, horizontal air track with...

    A 0.150 kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.730 m/s It has a head-on collision with a 0.305 kg glider that is moving to the left with a speed of 2.11 m/s. Suppose the collision is elastic. Find the magnitude of the final velocity of the 0.150 kg glider. Find the direction of the final velocity of the 0.150 kg glider. to the right to the left Find the...

  • A 0.149 kg glider is moving to the right on a frictionless, horizontal air track with...

    A 0.149 kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.900 m/s . It has a head-on collision with a 0.301 kg glider that is moving to the left with a speed of 2.18 m/s . Suppose the collision is elastic. Part A Find the magnitude of the final velocity of the 0.149 kg glider. Why can’t I use this equaton given to me by my professor: v1f=(m1-m2)/(m1+m2)*v1i?

  • Two air track carts move along an air track towards each other. Cart A has a...

    Two air track carts move along an air track towards each other. Cart A has a mass of 450 g and moves toward the right with a speed of 0.850 m/s. Cart B has a mass of 270 g and moves toward the left with a speed of 1.12 m/s. What is the total momentum of the two-cart system? Give your answer in kg m/s, to three significant firgures. Your Answer: Answer units

  • Question 6 - A cart on a horizontal air track has a fan attached to it....

    Question 6 - A cart on a horizontal air track has a fan attached to it. The mass of the cart plus fan is 357 g. The fan produces a force of 0.06 N that pushes the cart+fan system. Assume that there is no air resistance so that the only horizontal force is the force from the fan. Starting from rest, the cart takes 4.4 s to travel some fixed distance. Assume that the cart travels with constant acceleration. a)...

  • A 0.150 kg glider is moving to the right on a frictionless, horizontal air track with...

    A 0.150 kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.760 m/s . It has a head-on collision with a 0.292 kg glider that is moving to the left with a speed of 2.19 m/s . Suppose the collision is elastic. a) Find the magnitude of the final velocity of the 0.150 kg glider. b) Find the direction of the final velocity of the 0.150 kg glider. c) Find the magnitude...

  • A 0.157kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.850m/s . It has a hea...

    A 0.157kg glider is moving to the right on a frictionless, horizontal air track with a speed of 0.850m/s . It has a head-on collision with a 0.306kg glider that is moving to the left with a speed of 2.26m/s . Suppose the collision is elastic. Find the magnitude of the final velocity of the 0.157kg glider. Find the magnitude of the final velocity of the 0.306kg glider.

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT