Answer to Question #228196 in Physics for Ekott jnr

Question

If an 8kg mass is pulled up an incline at a constant speed ,determine
1)the tension in the string
2)the coefficient of friction between the 8kg mass and the surface (Assume there is no friction between the cord and the pulley )

Answer 1

Given:

$m=8.0\:\rm kg$

$v=\rm const$

$\theta$

1) the tension in the string

$$T=mg\sin\theta-F_{\rm fric}=mg\sin\theta-\mu mg\cos\theta$$

2) the coefficient of friction between the mass and the surface

$$\mu=\frac{F_{\rm fric}}{N}=\frac{T-mg\sin \theta}{mg\cos\theta}$$