Question

Problem 88

Answer 1

Given information

We are given that:

Initiall speed    

Kinetic friction      

Length of the sandy stretch    .

Step-by-step explanation

Step 1.

Free body diagram of the motorcycle:

from the free-body diagram for the cyclist in the sand, we can see that   since there is no vertical acceleration.

is the normal reaction and is the weight of the motorcycle

Now the frictional force   , where is the coefficient of friction. 

Now writing the equation of motion in the horiontal direction 

since the engine is off, there is only frictional force acting on the motorcycle opposite to the motion of the motorcycle, hence the negative sign

.