Question

an applied force of 50 newton is used to accelerate a 25 newton object to the right across a frictional surface.The object encounter 10 newton of friction .Draw a force diagram showing the forces acting on the object and determine the normal force , the mass and the acceleration of an object (neglect air resistance).

Answer 1

We are given $F = 50 N$, $mg = 25 N$, $F_f = 10 N$.

From projections of forces onto the vertical axis, normal force is $N = mg = 25 N$.

The mass is $m = \frac{25 N}{9.81 \frac{m}{s^2}} \approx 2.55 kg$.

According to second Newton's law, $ma = F - F_f$, from where the acceleration is$a = \frac{F - F_f}{m} = \frac{50 N - 10 N}{2.55 kg} \approx 15.7 \frac{m}{s^2}$.