Chapter 6, Problem 29A

Calculate the horizontal force that must be applied to a 1-kg puck to make it accelerate on a horizontal friction-free air table with the same acceleration it would have if it were dropped and fell freely.

To determine

Thehorizontal force to be applied to a puck of given mass and acceleration on a friction-free table

Answer to Problem 29A

The horizontal force to be applied on the puck is $9.8\text{ N}$

Explanation of Solution

Given:

A 1-kg puck is moved on a horizontal friction-free air table with an acceleration equal to that of free fall.

Formula used:

Using Newton’s second law of motion, a body experiencing a force F gets accelerated in the direction of the force and its magnitude a is proportional to magnitude of the applied force. It also holds an inverse relation with the mass of the body m . This can be expressed as,

  $F=ma$

In the case of free fall, the acceleration due to gravity is considered, given by g =9.8 m/s²

Calculation:

Here, mass of the puck is 1-kg and the acceleration is 9.8 m/s²

Substituting the parameters in the expression, the applied force can be obtained as,

  $\begin{array}{c}F=1\times 9.8\\ =9.8\text{ N}\end{array}$

Conclusion :

The horizontal force to be applied on the puck is $9.8\text{ N}$ .