Question

Block B has mass m and is released from rest when it is on top of wedge A, which has a mass 3m. Determine the tension in cord CD needed to hold the wedge from moving while B is sliding down A. Neglect friction.

• A. $2mgcos\theta$
• B. $\frac{mg}{2}cos2\theta$
• C. $\frac{mg}{2}sin2\theta$
• D. $mgsin2\theta$

Answer 1

The correct option is C

$\frac{mg}{2}sin2\theta$

$T=Nsin\theta ,N=mgcos\theta$

$T=mgsin\theta cos\theta$

$T=\frac{mg}{2}sin2\theta$