Question

A bicycle-chain wheel with a radius of 7.70 cm is attached to a chain that exerts a 35.0-n force on the wheel in the clockwise direction. what torque would be needed to keep the wheel from turning?

Answer 1

Torque,
`\tau=2.69\ N-m`

Step-by-step explanation:

It is given that,

Radius of the wheel, r = 7.7 cm = 0.077 m

Force exerted on the wheel, F = 35 N

To find,

Torque needed to keep the wheel from turning.

Solution,

We know that the product of force and distance is called torque. It is given by :

`\tau=r* F`

`\tau=0.077\ m* 35\ N`

`\tau=2.69\ N-m`

So, the torque needed to keep the wheel from turning is 2.69 N-m.

Answer 2

Torque on the wheel produced by the chain is given by,

τ= F×R= FRsin∅

here, R is the radius of the wheel = 7.70 cm=0.077 m

∅= angle between the action of force and point of contact = 90°(angle between wheel and the chain)

Substituting the values,

τ=
`35.0*0.077*sin90°`

= 2.6 N

It is the force exerted by the chain on the wheel. Therefore, a torque of 2.6 N would be needed to stop the wheel form turning.