There are three solids made up of aluminium,steel,and wood,of the same shape and same volume. Which of them would have the highest inertia?

$(a)$ Define force and state three possible effects of force on an object.
$(b)$ $A$ motorcycle is moving with a velocity of $90 \, km \, h^{-1}$ and it takes $5 \, s$ to stop after the brakes are applied. Calculate the force exerted by the brakes on the motorcycle if its mass along with the rider is $200 \, kg$.

The velocity versus time graph of a ball of mass $50 \, g$ rolling on a concrete floor is shown in the figure. Calculate the acceleration and the frictional force exerted by the floor on the ball.

The momentum of a body of given mass is proportional to its

State Newton's third law of motion. Give two examples.

$(a)$ $(i)$ Define momentum. State its $SI$ unit.
$(ii)$ An object of mass $50 \ kg$ is accelerated uniformly from a velocity of $4 \ m/s$ to $8 \ m/s$ in $8 \ s$. Find the magnitude of the force exerted on the object.
$(b)$ State Newton's first law of motion.