Question

A force $F = 75\, N$ is applied on a block of mass $5\, kg$ along the fixed smooth incline as shown in figure. Here gravitational acceleration $g = 10m/s^2$. The acceleration of the block is

• A. $5 \frac{m}{s^{2}}$ downwards the incline
• B. $5 \frac{m}{s^{2}}$ upwards the incline
• C. $510 \frac{m}{s^{2}}$ downwards the incline
• D. $10 \frac{m}{s^{2}}$ upwards the incline

Answer 1

Answer: (D)

$10 \frac{m}{s^{2}}$ upwards the incline

Answer 2

Consider the force acting on the block as shown below

Given, $F=75\, N$
$m=5\, kg$
Acceleration of the block
$F-m g \sin 30^{\circ} =m a$
$\Rightarrow a=\frac{F-m g \sin 30^{\circ}}{m}$
$\Rightarrow a =\frac{75-5 g \sin 30^{\circ}}{5}$
$a=\frac{50}{5}=10 m / s ^{2}$ upward to the inclined plane