Question

a 50kg sack of rice, resting on the ground, is dragged by a 100 N forceat 30 degrees with the horizontal. if the friction is 8N, what is the acceleration of the sack

Answer 1

Given:

$F=100\:\rm N$

$\theta=30^{\circ}$

$F_f=8\:\rm N$

$m=50\:\rm kg$

The Newton's second law says

$$ma_x=F_x$$

$$ma_x=F\cos\theta-F_f$$

$$a_x=\frac{F\cos\theta-F_f}{m}$$

$$a_x=\frac{100\cos30^{\circ}-8}{50}=1.57\:\rm m/s^2$$