7.7 Projectile motion 1

Question 1

Define projectile

Answer 1

a projected object in motion acted on only by the force of gravity

Question 2

What 3 key principles apply to all projectiles?

Answer 2

1. the acceleration of the object is always equal to g and is always downwards because the force of gravity acts downwards. The acceleration therefore ONLY affects the vertical motion of the object.
2. the horizontal velocity of the object is CONSTANT because the acceleration of the object doesn’t have a horizontal component.
3. the motions in the horizontal and vertical directions are independent of each other

Question 3

Why are 2 balls one of which vertically dropped and the other projected horizontally landing at the same time?

Answer 3

They are both pulled to the ground by the force of gravity which gives each ball a downward acceleration of g.

This downward acceleration doesn’t affect the horizontal motion of the ball projected horizontally— ONLY the vertical motion is affected.