Share
Explore BrainMass

Newton's Law Questions

I need help setting up and working through three more problems. Most of them I have attempted but could not make them work. Any help is appreciated!

Blocks of equal mass M sits on a plane inclined at 30 degrees to the horizontal. The coefficient of friction between the lower block (A) and the plane is 0.50 and between the upper block (B) is 0.30. (a) Find the acceleration of each block and the normal force exerted on A by B (b) What happens if the two blocks are reversed do that B leads the way down?

See attached file for full problem description.

Attachments

Solution Preview

Please see attached file.

Question: Blocks of equal mass M sit on a plane inclined at 30 degrees to the horizontal. The coefficient of friction between the lower block (A) and the plane is 0.50 and between the upper block (B) is 0.30.

(a) Find the acceleration of each block and the normal force exerted on A by B
(b) What happens if the two blocks are reversed so that B leads the way down?

Solution:

I've written the force each block exerts on the other as 'F' (see above)

Since the coefficient of friction for block B is less than for block A (and the masses are equal), it will experience less of a frictional force than A will. Therefore, B will always be pushing on A, wanting to go faster.

a) Writing the equation of motion for each block (sum of all forces = Ma)

...

Solution Summary

Newton's Law Questions are emphasized.

$2.19