Question

The two blocks in FIGURE$P7.34$are sliding down the incline. What is the tension in the massless string?

Short answer

Tension in the massless string is$0.613N$.

Step-by-step solution

Given information

Mass of the block, $m_1=1kg$

The coefficient of kinetic energy, ${\mu }_k=0.2$

Mass of the block, $m_2=2kg$

The coefficient of kinetic energy,${\mu }_k=0.1$

Explanation

Consider the equilibrium of force of $1kg$block in the direction of the plane

$F_1=1\times 9.81\sin 20-0.2\times 1\times 9.81\cos 20+T$

Consider the equilibrium of force of $2kg$block in the direction of the plane

$$\begin{gathered} F_2=2\times 9.81\sin 20-0.1\times 2\times 9.81\cos 20-T \\ {m}_{2}a=4.86N-T \\ \frac{T+1.51}{1}\times 2=4.86-T \\ T=0.613N \end{gathered}$$

Tension in the massless string is$0.613N$.