$A$ body of mass $500 \, g$ is at rest on a frictionless surface. Calculate the distance travelled by it in $10 \, s$ when acted upon by a force of $10^{-2} \, N$. (in $, m$)

$(a)$ Define momentum. Write its $SI$ unit.
$(b)$ $A$ car and a truck have the same momentum. Whose velocity is more and why?
$(c)$ $A$ bullet of mass $20 \ g$ moving with a speed of $500 \ m s^{-1}$ strikes a wooden block of mass $1 \ kg$ and gets embedded in it. Find the speed with which the block moves along with the bullet.

$(a)$ State Newton's first and third laws of motion.
$(b)$ $A$ car of mass $1800 \, kg$ moving with a speed of $10 \, m s^{-1}$ is brought to rest after covering a distance of $50 \, m$. Calculate the force acting on the car.

$(a)$ Using Newton's law of motion, derive the relation between force and acceleration.
$(b)$ Define one newton.
$(c)$ Which would require a greater force to accelerate: a $0.5 \, kg$ mass at $5 \, m s^{-2}$ or a $4 \, kg$ mass at $2 \, m s^{-2}$? Give reason.

State whether the following statement is true or false:
The force of friction is smaller in solids than in liquids.

Two objects,each of mass $1.5\, kg$,are moving in the same straight line but in opposite directions. The velocity of each object is $2.5\, m/s$ before the collision during which they stick together. What will be the velocity (in $m/s$) of the combined object after collision?