Energy of motion (kinetic energy) Knowledge-Based Download PDF

Questions

1. 1.

   An object of mass $m$ travels at a constant speed $v$. Which of the following modifications produces the greatest increase in its kinetic energy?

   • A) Doubling its mass while maintaining its speed
   • B) Doubling its speed while maintaining its mass
   • C) Increasing both its mass and its speed by 50%
   • D) Quadrupling its mass while halving its speed
2. 2.

   Which statement correctly describes the kinetic energy of a moving object?

   • A) It is a vector quantity that points in the direction of the object's motion.
   • B) It can have a negative value when the object travels in a negative coordinate direction.
   • C) It is directly proportional to the speed of the object.
   • D) It is a scalar quantity that is proportional to the square of the object's speed.
3. 3.

   If the speed of an object increases by 40%, by what percentage does its kinetic energy increase?

   • A) 96%
   • B) 80%
   • C) 40%
   • D) 196%
4. 4.

   A 2.0 kg cart moves east at 4.0 m/s, while a 3.0 kg cart moves west at 2.0 m/s along the same straight line. What is the total kinetic energy of the two-cart system?

   • A) 10 J
   • B) 16 J
   • C) 44 J
   • D) 22 J
5. 5.

   A 2.0 kg object moves across a flat surface with perpendicular velocity components of 6.0 m/s along the x-axis and 8.0 m/s along the y-axis. What is the kinetic energy of the object?

   • A) 14 J
   • B) 50 J
   • C) 100 J
   • D) 196 J
6. 6.

   A constant net horizontal force of 25 N acts on an initially stationary 5.0 kg box, displacing it by 8.0 m across a frictionless floor. What is the final kinetic energy of the box?

   • A) 200 J
   • B) 100 J
   • C) 80 J
   • D) 40 J
7. 7.

   A 4.0 kg cart initially traveling at a speed of 3.0 m/s accelerates along a frictionless horizontal track to a final speed of 5.0 m/s. What is the net increase in the cart's kinetic energy?

   • A) 8.0 J
   • B) 18 J
   • C) 32 J
   • D) 50 J
8. 8.

   Two objects, X and Y, have masses of 2 kg and 8 kg, respectively, and possess the same kinetic energy. What is the ratio of the speed of object X to the speed of object Y?

   • A) 1 : 4
   • B) 1 : 2
   • C) 4 : 1
   • D) 2 : 1
9. 9.

   A vehicle with a mass of 1200 kg travels along a straight road with a kinetic energy of 240 kJ. What is the speed of the vehicle?

   • A) 10 m/s
   • B) 20 m/s
   • C) 40 m/s
   • D) 400 m/s
10. 10.

    An object of mass $m$ moving at speed $v$ has a kinetic energy of $E$. If its mass is reduced to $\frac{m}{2}$ and its speed is increased to $3v$, what is its new kinetic energy in terms of $E$?

    • A) 1.5E
    • B) 3.0E
    • C) 3.5E
    • D) 4.5E