Which of the following statements is not correct for an object moving along a straight path in an accelerated motion?

Identify the type of inertia experienced by the brain,when
$(a)$ the head is hit suddenly with a stick.
$(b)$ a car is suddenly made to stop using brakes.
$(c)$ a boxer punches another boxer in the face.

If a body experiences a net zero unbalanced force, then the body:

Two forces $F_{1} = 20 \, N$ and $F_{2} = 30 \, N$ are acting on an object in opposite directions as shown in the figure.
$(i)$ What is the net force acting on the object?
$(ii)$ What is the direction of the net force acting on the object?
$(iii)$ If the mass of the body is $10 \, kg$,what will be the acceleration produced in it?

$A$ car starts from rest and rolls down a hill with constant acceleration. It travels a distance of $800 \ m$ in $10 \ s$. Find its acceleration. Also,find the force acting on it if its mass is $800 \ kg$.

Action-reaction forces act