Question

Question: A projectile is launched at some angle to the horizontal with some initial speed v_iand air resistance is negligible (a)Is the projectile a freely falling object? (b) what is its acceleration in the vertical direction ? (c) what is its acceleration in horizontal direction?

Short answer

(a) Yes, it is a freely falling object.

(b) The acceleration acting in vertical direction is acceleration due to gravity.

(c) No acceleration acts in the horizontal direction.

Step-by-step solution

Definition of free fall

Free fall is the condition in which an object is accelerated towards earth due to the force of gravitation. Any another force is generally absent or there may be minor forces such as air resistance, which can be neglected.

Analyzing each option.

(a): Since, projectile is thrown at an angle with horizontal, under the action of acceleration due to gravity it is still a freely falling.

(b): the acceleration in vertical direction is acceleration due to gravity ‘g’ acting downward to the center of earth. It is responsible for changing only the vertical component of the velocity. Thus, the acceleration acting in vertical direction is acceleration due to gravity.

(c): in horizontal direction there is no acceleration and hence throughout the motion the horizontal component of velocity remains unchanged.