Impulse Knowledge-Based Practice

Questions

1. 1.

   A constant net force of 24 N acts on an object along a straight line, delivering an impulse that changes the object's momentum from 12 kg·m/s to 84 kg·m/s in the direction of the force. What is the duration of time over which this force acts on the object?

   • A) 3.0 s
   • B) 3.5 s
   • C) 4.0 s
   • D) 0.33 s
2. 2.

   Two carts with masses of 2.0 kg and 6.0 kg are initially at rest on a frictionless horizontal track. If the same constant horizontal net force acts on each cart for an equal duration of 3.0 s, what is the ratio of the magnitude of the impulse delivered to the 2.0 kg cart to that delivered to the 6.0 kg cart?

   • A) 1 : 3
   • B) 1 : 1
   • C) 3 : 1
   • D) 1 : 9
3. 3.

   A net force acting on an object along a straight line has a value of +12 N for 3.0 s and then -4.0 N for the subsequent 2.0 s. What is the net impulse delivered to the object over the entire 5.0 s interval?

   • A) +44 N·s
   • B) +36 N·s
   • C) +28 N·s
   • D) +20 N·s
4. 4.

   A 0.50 kg puck sliding east across a frictionless horizontal surface at 4.0 m/s is struck by an impulse, causing it to travel north at 3.0 m/s. What is the magnitude of the impulse delivered to the puck?

   • A) 0.50 N·s
   • B) 3.5 N·s
   • C) 5.0 N·s
   • D) 2.5 N·s
5. 5.

   An object of mass $m$ is initially at rest on a frictionless horizontal surface. If a net force delivers an impulse of magnitude $J$ to the object, what is its resulting kinetic energy?

   • A) $\frac{J^2}{m}$
   • B) $\frac{J^2}{2m}$
   • C) $\frac{J^2}{4m}$
   • D) $\frac{2J^2}{m}$
6. 6.

   A net horizontal force acting on an object increases uniformly from 0 N to 50 N over a time interval of 4.0 s. What is the magnitude of the impulse delivered to the object during this time interval?

   • A) 50 N·s
   • B) 100 N·s
   • C) 150 N·s
   • D) 200 N·s
7. 7.

   A 0.40 kg soccer ball initially at rest is kicked, reaching a speed of 25 m/s. If the player's foot is in contact with the ball for 0.020 s, what is the magnitude of the average net force exerted on the ball during the kick?

   • A) 500 N
   • B) 1250 N
   • C) 250 N
   • D) 10 N
8. 8.

   A 2.0 kg cart moving along a horizontal track at 3.0 m/s to the right is subjected to an impulse of 10 N·s directed to the left. What is the final velocity of the cart?

   • A) 8.0 m/s to the right
   • B) 2.0 m/s to the left
   • C) 2.0 m/s to the right
   • D) 5.0 m/s to the left
9. 9.

   A constant horizontal braking force of 250 N is applied to a rolling cart for a duration of 1.6 s to bring it to a complete stop. What is the magnitude of the impulse delivered to the cart during this time interval?

   • A) 156 N·s
   • B) 400 N·s
   • C) 500 N·s
   • D) 640 N·s
10. 10.

    A 2.5 kg ball traveling horizontally at 8.0 m/s strikes a rigid wall and rebounds in the opposite direction along the same line at 6.0 m/s. What is the magnitude of the impulse exerted by the wall on the ball?

    • A) 5.0 N·s
    • B) 20.0 N·s
    • C) 35.0 N·s
    • D) 50.0 N·s

Answers and step-by-step solutions appear after you finish the test.