Question

a wooden block of mass 2kg is placed on a horizontal surface.a horizontal force of 12N is exerted on it makes it to accelerate at 5m/s^-2 .find the frictional force acting between the surface

Answer 1

To find the frictional force acting between the surface and the wooden block, we can use Newton's second law of motion:

\[
F_{net} = m \cdot a
\]

where:

- \( F_{net} \) is the net force acting on the block,
- \( m \) is the mass of the block,
- \( a \) is the acceleration of the block.

Given:
- Mass (\( m \)) = 2 kg
- Acceleration (\( a \)) = 5 m/s²
- Applied force (\( F_{applied} \)) = 12 N

1. **Calculate the net force (\( F_{net} \))**:

\[
F_{net} = m \cdot a = 2 \, \text{kg} \cdot 5 \, \text{m/s}^2 = 10 \, \text{N}
\]

2. **Determine the frictional force (\( f \))**:

The net force is the difference between the applied force and the frictional force:

\[
F_{net} = F_{applied} - f
\]

Rearranging this gives:

\[
f = F_{applied} - F_{net}
\]

Substituting in the values we have:

\[
f = 12 \, \text{N} - 10 \, \text{N} = 2 \, \text{N}
\]

Thus, the frictional force acting between the surface and the block is **2 N**.