College Physics 4.6 – Force necessary for a rocket sled deceleration


The same rocket sled drawn in Figure 4.30 is decelerated at a rate of 196 m/s². What force is necessary to produce this deceleration? Assume that the rockets are off. The mass of the system is 2100 kg. 

The same rocket sled drawn in Figure 4.30 is decelerated at a rate of 196 m/s2 . What force is necessary to produce this deceleration? Assume that the rockets are off. The mass of the system is 2100 kg.
Figure 4.30: The rocket sled

Solution:

From the problem, we know that the acceleration a is 196 m/s² and the mass is 2100 kg. We are asked to solve for the net force F. Basically, we can compute for the net force using the Second Law of Motion by Newton. 

\displaystyle \text{net F}=\text{ma}

\displaystyle \text{net F}=\left(2100\:\text{kg}\right)\left(196\:\text{m/s}^2\right)

\displaystyle \text{net F}=411,600\:\text{N}       ◀

The net force opposing motion should be 411,600 Newtons to produce the given deceleration.