ANSWER: The centripetal force is always perpendicular to the direction of motion. Only the component of the force in the direction of motion can do work. The centripetal force has no such component, so it can never do work. A record turntable starts to rotate with increasing angular velocity.

A centripetal force is a net force that acts on an object to keep it moving along a circular path.

The centripetal force can also be supplied as a ‘push’ force, such as in the case where the normal reaction of a wall supplies the centripetal force for a wall of death rider. Newton’s idea of a centripetal force corresponds to what is nowadays referred to as a central force.

Key terms

1. Its role is to serve as a centripetal force against the centrifugal tendencies of the ministries. 2. The centripetal force is inversely proportional to the square of the distance from the centre.

Centrifugal force, a fictitious force, peculiar to a particle moving on a circular path, that has the same magnitude and dimensions as the force that keeps the particle on its circular path (the centripetal force) but points in the opposite direction.

The centrifugal force is a pseudo-force because if the centripetal force ceased for an object in circular motion, the centrifugal force the body is “feeling” would instantly disappear, and the object would travel tangentially to its line of motion.

With this definition, centripetal force would be real and centrifugal not real. Centripetal force is the force needed to make something move in a circle. A constant magnitude centripetal force that is always perpendicular to the direction of motion will make the object move in a circle.

5 Answers. Because the rotation of the earth is very smooth and doesn’t change, the centripetal acceleration we feel is very nearly constant. This means that the (small) centrifugal force from the rotation gets added to gravity to make up the “background force” we don’t notice.

As we found the centripetal force is the force applied due to centripetal acceleration and the force is not responsible for the displacement of the particle. So, the displacement is zero therefore the work done is also zero.

Since, the particle always moves in a direction perpendicular to the radial direction in circular motion. Therefore, the dot product is always zero and hence, the work done by centripetal force in a circular motion is always zero.

Note that the centripetal force is proportional to the square of the velocity, implying that a doubling of speed will require four times the centripetal force to keep the motion in a circle.

The centripetal force is directly proportional to the square of the circular speed for uniform circular motion.

Three factors which affect the centripetal force are:

• mass of the object;
• its speed;
• the radius of the circle.

Static friction is what enables you to hold objects without it slipping away from your fingers. Static friction allows the floor to “push back” against your wheels, allowing you to turn left. In this case the only force that is acting in the direction of turn(centripetal force) is the frictional force.

The magnitude F of the centripetal force is equal to the mass m of the body times its velocity squared v 2 divided by the radius r of its path: F=mv2/r. According to Newton’s third law of motion, for every action there is an equal and opposite reaction.

Centripetal force is measured in Newtons and is calculated as the mass (in kg), multiplied by tangential velocity (in meters per second) squared, divided by the radius (in meters).