All Exams Test series for 1 year @ ₹349 only
Question

A student pushes a heavy box that is already moving across a rough floor. If the force applied by the student is exactly equal to the frictional force opposing the motion, what will happen to the box?

The correct answer is

The box will move at a constant speed

To solve this problem, we need to understand the dynamics of motion under the influence of forces, particularly when the net force is zero.

Explanation:

  • When an object is moving across a surface, it is subjected to various forces, including the force exerted by the person and the frictional force from the surface.
  • Frictional force is a resistive force that opposes the relative motion of two surfaces in contact. In this case, it's opposing the motion of the box.
  • According to Newton's First Law of Motion, an object will continue in its state of rest or uniform motion unless acted upon by a net external force. This implies that if the forces acting on the object are balanced, the object will continue its motion with constant velocity.

When the force applied by the student is exactly equal to the frictional force, the forces cancel each other out, resulting in a net force of zero. Since the net force is zero, there is no change in the box's velocity.

Conclusion:

Thus, the box will continue to move at a constant speed.

Justification of Options:

  • The box will move at a constant speed (Correct answer): With balanced forces (net force = 0), the box maintains its current speed.
  • The box will gradually come to rest: This would occur if the frictional force were greater than the applied force, resulting in deceleration.
  • The box will move at an increasing speed: This would happen if the applied force were greater than the frictional force, resulting in acceleration.
  • The box will accelerate forward: Similar to moving at increasing speed, this requires a greater applied force than frictional resistance.
Was this answer helpful?

Similar Questions

  1. Which of the following best describes the velocity-time graph for an object moving with uniform velocity?

  2. A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?

  3. Which experimental discovery contradicted Thomson's model of the atom and led to its rejection?

  4. Which of the following best describes how sound travels through air?

  5. Which of the following statements best describes the behavior of magnetic field lines around a straight current-carrying conductor?

  6. A factory plans to install a powerful electromagnet for lifting metal scraps. To maximize the magnetic field strength around the coil, which of the following combinations would be most effective?

  7. Which of the following statements best describes the behavior of magnetic field lines around a straight current-carrying conductor?

  8. A construction worker needs to lift a heavy metal beam using a lever but has a limited length of plank. Which adjustment would allow the worker to lift the beam with the least effort if the position of the fulcrum can be changed but the plank length remains constant?

  9. A student pushes a heavy box that is already moving across a rough floor. If the force applied by the student is exactly equal to the frictional force opposing the motion, what will happen to the box?

  10. A factory plans to install a powerful electromagnet for lifting metal scraps. To maximize the magnetic field strength around the coil, which of the following combinations would be most effective?


Important Questions from Physics

  1. Ultrasonic sounds are the sounds which have frequencies?

  2. What is the colour of the light emitted by the Sun?

  3. What is the resultant resistance of 3 Ω and 6 Ω resistances connected in series?

  4. Lightning occur in the sky when two clouds:

  5. With reference to street-lighting, how do sodium lamps differ from LED lamps?

    1. Sodium lamps produce light in 360 degrees but it is not so in the case of LED lamps.

    2. As street lights, sodium lamps have a longer life span than LED lamps.

    3. The spectrum of visible light from sodium lamps is almost monochromatic while LED lamps offer significant colour advantages in street lighting.

    Select the correct answer using the code given below.  

Need Expert Advice?
Test Series
RRB JE img
Railways
RRB JE Prev. Yr. Paper (CBT 1 + CBT 2) Test Series
290 Tests 5 Tests Free
4821 Attempts
4.3(89)
English

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App