Q 6. A stone of 1 kg is thrown with a velocity of 20 m s-1 across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?
By the equation of motion, we know that,
or (Since ball comes to rest thus final velocity is zero.)
The acceleration is negative. This implies that the force is opposing the motion.
The force is given by :
Hence the frictional force between stone and ice is 4 N.