On the Move

Question 1

What equation describes the speed of an object moving at constant speed about a circle, radius r?

Answer 1

V = 2πr/T, where T is time taken to move around the circle once.

Question 2

What three principles apply to all projectiles?

Answer 2

• The acceleration of the object is always equal to g and is always downwards.
• The horizontal velocity of the object is unaffected because the acceleration of the object does not have a horizontal component.
• The motions in the horizontal and vertical planes are independent of each other.

Question 3

What is the difference between speed and distance and velocity and displacement?

Answer 3

Speed and distance are scalar as they have no direction. Velocity and displacement are vectors as they have magnitude and direction.