Q 11-04-047NEETJEE MainMedium
A box lies on the floor of a truck. The coefficient of kinetic friction between them is $0.3$. The truck accelerates at $5\ \text{m/s}^2$, which is enough to make the box slide. The acceleration of the box relative to the truck is ($g = 10\ \text{m/s}^2$)
Answer: (D) $2\ \text{m/s}^2$ towards the rear
Relative to the ground, kinetic friction drives the box forward at $\mu_k g = 3\ \text{m/s}^2$, while the truck accelerates at $5\ \text{m/s}^2$.
Relative to the truck: $3 - 5 = -2\ \text{m/s}^2$, i.e. $2\ \text{m/s}^2$ towards the rear.
Solution by Sreeraj P, M.Sc Physics