A projectile is fired at an angle of elevation of 30°.Neglecting air resistance,what are possible angles in flight between the acceleration vector and the velocity vector?
A)160° and 40°
B)20° and 70°
C)90° and 30°
D)none of the above
E)10° and 30°

Question

Quizplus · Accepted Answer

When a projectile is fired at an angle of elevation of 30°, the initial velocity can be resolved into two components: vertical and horizontal. Neglecting air resistance, the vertical acceleration is constant and equal to the acceleration due to gravity, directed downwards. The horizontal acceleration is zero, as there is no force acting in that direction. Therefore, the velocity vector remains horizontal throughout the flight and the acceleration vector is always vertical. This means that the angle between the acceleration vector and the velocity vector is always 90°. Thus, the only possible answer is C: 90° and 30° (the angle of elevation).

A Projectile Is Fired at an Angle of Elevation of 30°.Neglecting