motion questions???

[Bestie]

Two questions please:

1.  a mass of 25kg is on a rough horizontal floor. A horizontal force of 60N to the left is acted on the mass. Total frictional force opposing motion is 5N. What would be the acceleration is the force is applied at an angle of 45 degrees to the horizontal

2. mass of 20kg at rest on a plane inclined at 25 degrees to the horizontal. WHat is the component of weight acting down on plane? i know the one acting perpendicular is the normal but parallel?

thank you

[Phenomenol]

Two questions please:

1.  a mass of 25kg is on a rough horizontal floor. A horizontal force of 60N to the left is acted on the mass. Total frictional force opposing motion is 5N. What would be the acceleration is the force is applied at an angle of 45 degrees to the horizontal

2. mass of 20kg at rest on a plane inclined at 25 degrees to the horizontal. WHat is the component of weight acting down on plane? i know the one acting perpendicular is the normal but parallel?

thank you

1. - Find the horizontal component of the force applied on the mass.
- Find the net force on the mass, and then the acceleration.

2. - This question is best done with a diagram. The perpendicular component of weight is indeed equal to the normal reaction on the mass in magnitude. If you can find that, then finding the parallel component should be straightforward (mgsin(25)).

The easiest way to visualise the components is with a right angled triangle, with the hypotenuse having the full magnitude of the weight force.
Also, note the only way that the mass is at rest on an inclined plane is if the parallel component of the weight force is opposed by friction.