Question

What is common to the variation in the range and the height of a projectile?

a - horizontal velocity
b- time of flight vertical velocity, horizontal acceleration

c - vertical velocity

d - horizontal acceleration

Answer 1

Projectile motion (i.e velocity and acceleration) is decomposed into x-axis and y-axis components. The y-axis element of time in flight is dependent on initial velocity, so b and c are out, since initial velocity can be anything The x-axis element of horizontal velocity is also dependent on initial velocity, so a is out. This leaves d. In the absence of air drag there will be no acceleration or deceleration in the x-axis component , therefore, there is no variation because it is always zero. Thus, d is the best choice.

Does this make sense?