Question

Find the normal force and acceleration respectively of the $2\text{kg}$ block shown in the figure.
$\text{(Take}g=10{\text{m/s}}^2\text{)}$

• A. $4\text{N},6{\text{m/s}}^2$
• B. $6\text{N},4{\text{m/s}}^2$
• C. $3\text{N},2{\text{m/s}}^2$
• D. $2\text{N},3{\text{m/s}}^2$

Answer 1

The correct option is A $4\text{N},6{\text{m/s}}^2$

Let us draw the FBD of block first

From the FBD, we normal force as
$N+20\sin {53}^{\circ }=2g$
$\Rightarrow N+20\sin {53}^{\circ }=20$
$\Rightarrow N+16=20\Rightarrow N=4\text{N}$
Now, acceleration $a$ of the body is due to horizontal component of the force, which is given by
$a=\frac{20\cos {53}^{\circ }}{2}=\frac{12}{2}=6{\text{m/s}}^2$