Impulse–momentum theorem Knowledge-Based Download PDF

Questions

1. 1.

   Two carts, Cart 1 of mass 2.0 kg and Cart 2 of mass 6.0 kg, are initially at rest on a frictionless horizontal surface. If identical constant net horizontal forces act on each cart for the same duration of time, what is the ratio of the final speed of Cart 1 to that of Cart 2?

   • A) 3.0
   • B) 1.0
   • C) 0.33
   • D) 9.0
2. 2.

   A net force acting along the line of motion of an object increases uniformly from 0 N to 80 N over a time interval of 3.0 s. What is the magnitude of the change in momentum of the object during this interval?

   • A) 60 kg·m/s
   • B) 120 kg·m/s
   • C) 240 kg·m/s
   • D) 360 kg·m/s
3. 3.

   An object of mass $m$ moving with an initial speed $v$ along a straight line is brought to rest by a constant net retarding force of magnitude $F$ in a time interval $\Delta t$. If the object's initial speed is doubled to $2v$ and the retarding force magnitude is also doubled to $2F$, what is the new time interval required to bring the object to rest?

   • A) $\Delta t$
   • B) $2\Delta t$
   • C) $4\Delta t$
   • D) $\frac{1}{2}\Delta t$
4. 4.

   A 2.0 kg ball moving horizontally due east at 3.0 m/s is struck so that it moves horizontally due north at 4.0 m/s. What is the magnitude of the impulse delivered to the ball?

   • A) 2.0 N·s
   • B) 10 N·s
   • C) 14 N·s
   • D) 5.0 N·s
5. 5.

   A 1200 kg car moving along a straight horizontal road slows down from 25 m/s to 10 m/s due to braking. What is the magnitude of the impulse exerted on the car during this time?

   • A) 12 000 N·s
   • B) 42 000 N·s
   • C) 18 000 N·s
   • D) 30 000 N·s
6. 6.

   A constant net horizontal force of 24 N acts on an object initially at rest on a frictionless surface for 1.5 s. If the object reaches a speed of 8.0 m/s, what is the mass of the object?

   • A) 3.0 kg
   • B) 4.5 kg
   • C) 6.0 kg
   • D) 12 kg
7. 7.

   A constant net force of 35 N acts on an object along its line of motion to increase its momentum from 25 kg·m/s to 165 kg·m/s. For what duration of time does this force act on the object?

   • A) 2.5 s
   • B) 4.0 s
   • C) 4.7 s
   • D) 5.4 s
8. 8.

   An object moving along a straight line has an initial momentum of 480 kg·m/s. If a constant net force of 120 N acts on the object in the direction of its motion for 2.5 s, what is its final momentum?

   • A) 180 kg·m/s
   • B) 300 kg·m/s
   • C) 780 kg·m/s
   • D) 600 kg·m/s
9. 9.

   A 0.50 kg rubber ball traveling horizontally at 14 m/s strikes a vertical wall and rebounds horizontally in the opposite direction at 10 m/s. If the collision lasts for 0.040 s, what is the magnitude of the average force exerted by the wall on the ball?

   • A) 50 N
   • B) 120 N
   • C) 180 N
   • D) 300 N
10. 10.

    A 4.0 kg object moves to the right with a velocity of 5.0 m/s along a frictionless surface when a constant net horizontal force of 12 N directed to the left acts on it for 3.0 s. What is the final velocity of the object?

    • A) 4.0 m/s to the left
    • B) 4.0 m/s to the right
    • C) 14 m/s to the right
    • D) 9.0 m/s to the left