Centripetal Acceleration

Question 1

Define Centripetal acceleration

Answer 1

• For an object moving in uniform circular motion, its centripetal acceleration = v²/r = ω²r towards the centre of the circle.
• For a satellite in a circular orbit, its centripetal acceleration is g = v²/r

Question 2

Define centripetal force

Answer 2

The resultant force on an object that moves along a circular path. For an object of mass moving along a circular path, the centripetal force = (mv²⁾/r towards the centre of the circle.

Question 3

Why is velocity not constant when an object is travelling uniformly in a circle?

Answer 3

• Linear speed, is constant but the direction changes as object goes round in a circle, because its velocity is changing it is accelerating.
• The acceleration is caused by a force F towards the centre (centripetal).

Question 4

To make an object move around on a circular path:

Answer 4

It must be acted on by a resultant force that changes its direction of motion.

Question 5

Forces which may be the cause of a force towards the centre are:

Answer 5

• Tension in a string
• Gravity
• Electrostatic force of attraction
• Friction
• Magnetic force