Question

A force is applied to a block to move it up a 30° incline. The incline is frictionless, the block is initially at rest, F= 65.0 N and M=5.00 kg. If the block starts from rest, how far will it move in 0.550 s? Also, indicate whether the block moves up or down the incline.

Answer 1

Answer:

0.96 m, upward

Explanation:

$\theta=30^{\circ}$

$F=65 N$

$M=5 kg$

Initial velocity, u=0

$t=0.550 s$

$Fcos\theta-Mgsin\theta=Ma$

Where $g=9.8 m/s^2$

Substitute the values

$65cos30-5\times 9.8sin30=5a$

$31.8=5a$

$a=\frac{31.8}{5}=6.36 m/s^2$

$S=ut+\frac{1}{2}at^2$

$S=0+\frac{1}{2}(6.36)(0.55)^2=0.96 m$

Hence,the block moves upward because displacement is positive.