Work done by cord on the pulley

[annamal]

Homework Statement

A 2-kg block on a frictionless inclined plane with an angle 40 degrees from the hoizontal. It has a cord attached to a pulley of mass 1 kg
and radius 20 cm. The acceleration of the block down the plane is 5 m/$s^2$ (b) What is the work done by the cord on the pulley?

Relevant Equations

W = F*d
$W = \Delta(0.5*I*w^2)$

torque = rF = I*aT/r
F = 0.5*aT*m_p
W = F (tension in rope)*d = 0.5*aT*m_p*d

Don't know because of unknown d

 

[kuruman]

Homework Statement:: A 2-kg block on a frictionless inclined plane with an angle 40 degrees from the hoizontal. It has a cord attached to a pulley of mass 1 kg
and radius 20 cm. The acceleration of the block down the plane is 5 m/$s^2$ (b) What is the work done by the cord on the pulley?
Relevant Equations:: W = F*d
$W = \Delta(0.5*I*w^2)$

View attachment 299267
torque = rF = I*aT/r
F = 0.5*aT*m_p
W = F (tension in rope)*d = 0.5*aT*m_p*d

Don't know because of unknown d

Looks like you are asking about part (b) without having shown us part (a). Maybe d is given in part (a).

 

[vela]

Don't know because of unknown d.

It's a mistake in the book. The distance the block slides down the incline is 50 cm.

 

[annamal]

Looks like you are asking about part (b) without having shown us part (a). Maybe d is given in part (a).

I figured out part a.
Part a just says "What is the acceleration of the block down the plane?" which I gave as 5 m/$s^2$

 

[annamal]

It's a mistake in the book. The distance the block slides down the incline is 50 cm.

I see that. I am submitting an errata to openstax.