Review question

# How fast are these particles sliding when they pass? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R6864

## Question

Two particles $A$ and $B$ are placed side by side on rough horizontal ground, and are simultaneously projected along the ground in the same direction with speeds $\quantity{14}{m\,s^{-1}}$ and $\quantity{21}{m\,s^{-1}}$ respectively. $A$ comes to rest after travelling $\quantity{70}{m}$, and $B$ after travelling $\quantity{35}{m}$. Calculate the coefficient of friction between each particle and the ground, and show that the times for which the particles are in motion are in the ratio $3:1$.

Show also that $A$ passes $B$ before either particle comes to rest, and calculate the speed of each particle when this happens.

Take $g$ to be $\quantity{9.8}{m\,s^{-2}}$.