Question

Superman throws a 2400 n boulder at a villain. what horizontal force must superman apply to the boulder to give a horizontal acceleration of 12.0 m/s2?

Answer 1

The boulder has a weight of W=2400 N. The weight of an object is the product between its mass m and the gravitational acceleration g:
$W=mg$
Rearranging the relationship, we can calculate the mass of the boulder:
$m= \frac{W}{g}= \frac{2400 N}{9.81 m/s^2}=244.6 kg$

We are told that Superman applies a horizontal force to this object, and as a result, the acceleration of the boulder is $a=12.0 m/s^2$. We can find the force applied by using Netwon's second law of motion:
$F=ma=(244.6 kg)(12.0 m/s^2)=2935 N$