Chapter 6, Problem 28A

Calculate the acceleration if you push with a 20-N horizontal force against a 2-kg block on a horizontal friction-free air table.

$F=ma$

To determine

Theacceleration of a block of given mass, for an applied horizontal force over a frictionless surface

Answer to Problem 28A

The acceleration of the block is $5\text{}{\text{m/s}}^2$

Explanation of Solution

Given:

A block of mass 2-kg is pushed across a horizontal friction-free air table using a force of 20-N

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,

  $F=ma$

For a given force and mass of the object, the acceleration can be calculated as,

  $a=\frac{F}{m}$

The assumption of a frictionless surface is considered.

Calculation:

Here, force experienced by the block of mass 2-kg is 20-N. (or 20 kg-m/s² ). Substituting these values, the acceleration is obtained as,

  $\begin{array}{c}a=\frac{20}{2}\\ {\text{=10 m/s}}^2\end{array}$

Conclusion :

The acceleration of the given block for an applied force is $5\text{}{\text{m/s}}^2$ .