Q12 of 57 Page 97

If the tension in the string in figure (6-E3) is 16 N and the acceleration of each block is 0.5 m/s2, find the friction coefficients at the two contacts with the blocks.




The free body diagram of the given problem is shown above.


From figure (a)


μ1R + ma = T


μ1R + 2(0.5) = 16 {R = mg cosθ}


⇒ μ1(2g) =15


⇒ μ1 = 0.75


From figure (b)


μ2R + ma = F − mg sin θ


⇒μ2mg cos θ + 4 (0.5) = 16 − 4g sin 30°


⇒μ2 = 0.06


More from this chapter

All 57 →
10

The angle between the resultant contact force and the normal force exerted by a body on the other is called the angle of friction. Show that, if λ be the angle of friction and μ the coefficient of static friction,

11

Consider the situation shown in figure (6-E2). Calculate (a) the acceleration of the 1.0 kg blocks, (b) the tension in the string connecting the 1.0 kg block, and (c) the tension in the string attached to 0.50 kg.


 13

The friction coefficient between the table and the block shown in figure (6-E4) is 0.2. Find the tensions in the two strings.


14

The friction coefficient between a road and the tyre of a vehicle is 4/3. Find the maximum incline the road may have so that once hard brakes are applied and the wheel starts skidding, the vehicle going down at a speed of 36 km/hr is stopped within 5 m.