Question

1. a force f acts in the forward direction on a bag of cement of mass m. a friction force f opposes this motion. if the bag of cement has a mass of 7 kg, the applied force is 17 n and the frictional force is 7 n. the acceleration of the bag of cement is (a) 1 m/s² (b) 3 m/s² (c) 0.45 m/s² (d) none of the above

Explanation:

Step1: Calculate net force

According to Newton's second - law, the net force $F_{net}$ is the difference between the applied force $F$ and the frictional force $f$. So $F_{net}=F - f$. Given $F = 17\ N$ and $f = 7\ N$, then $F_{net}=17 - 7=10\ N$.

Step2: Use Newton's second - law to find acceleration

Newton's second - law is $F_{net}=ma$, where $m$ is the mass and $a$ is the acceleration. We know $m = 7\ kg$ and $F_{net}=10\ N$. Rearranging the formula for $a$, we get $a=\frac{F_{net}}{m}$. Substituting the values, $a=\frac{10}{7}\approx1.43\ m/s^{2}$.

Answer:

(d) none of the above