# physics

posted by .

A 10.0-kg block is at rest on a horizontal floor. If you push horizontally on the 10.0-kg block with a force of 20.0 N, it just starts to move.
(a) What is the coefficient of static friction?

b) A 12.0-kg block is stacked on top of the 10.0-kg block. What is the magnitude F of the force, acting horizontally on the 10.0-kg block as before, that is required to make the two blocks start to move?

• physics -

Fb = 10kg * 9.8 = 98N = Force of block.

Fb = Fv = 98N,

a. Fh - u*Fv = 0,
20 - 98u = 0,
98u = 20,
u = 20 / 98 = 0.20.

b. Fb = (10 + 12)kg * 9.8 = 215.6N.
= Force of blocks.

Fv = Fb = 215.6N.

Fh - u*Fv = 0,
Fh = u*Fv = 0.2 * 215.6 = 43.1N = Force required to move the blocks.

## Similar Questions

1. ### Physics

A 4.0-kg block is at rest on a horizontal floor. If you push horizontally on the 4.0-kg block with a force of 12.0 N, it just starts to move. What is the coefficient of static friction?
2. ### College Physics

A 3.0 kg black is at reat on a horizontal floor. If you push horizontally on the 3.0 kg block with a force of 12.0 N, it just starts to move. What is the coefficient of static friction?
3. ### Physics

A 3.0-kg block is at rest on a horizontal floor. If you push horizontally on the 3.0-kg block with a force of 12.0N it just starts to move. What is the coefficient of static friction?
4. ### physics

A 5.0-kg block is at rest on a horizontal floor. If you push horizontally on the 5.0-kg block with a force of 10.0 N, it just starts to move. (a) What is the coefficient of static friction?

A 5.0-kg block is at rest on a horizontal floor. If you push horizontally on the 5.0-kg block with a force of 10.0 N, it just starts to move. (a) What is the coefficient of static friction?
6. ### physics

The coefficient of static friction between a block and a horizontal floor is 0.35, while the coefficient of kinetic friction is 0.12. The mass of the block is 4.5 kg. A horizontal force is applied to the block and slowly increased. …
7. ### physics

The coefficient of static friction between a block and a horizontal floor is 0.40, while the coefficient of kinetic friction is 0.15. The mass of the block is 5.0 kg. A horizontal force is applied to the block and slowly increased. …
8. ### physics

The coefficient of static friction between a block and a horizontal floor is 0.40, while the coefficient of kinetic friction is 0.15. The mass of the block is 5.0 kg. A horizontal force is applied to the block and slowly increased. …
9. ### physics

The coefficient of static friction between a block and a horizontal floor is 0.40, while the coefficient of kinetic friction is 0.15. The mass of the block is 5.0 kg. A horizontal force is applied to the block and slowly increased. …
10. ### physics

The coefficient of static friction between a block and a horizontal floor is 0.414, while the coefficient of kinetic friction is 0.107. The mass of the block is 4.03 kg. A horizontal force is applied to the block and slowly increased. …

More Similar Questions