# Mechanics M1 question. Motion of a block on a slope

1. Jun 6, 2009

### Vanagib

1. The problem statement, all variables and given/known data
A block of mass 12kg slides down a slope at 5deg to the horizontal. The speed of the block at the top of the slop is 1.5ms^-1
There is a constant resistance to motion of 15N

iii) Calculate the acceleration of the block in the direction of its motion
iv) For how much time does the block slide down the slope before coming to rest and how far does it slide in that time?

2. Relevant equations
F=ma

3. The attempt at a solution
F=ma
F = 12a

I cannot work out what the resultant force is. I'm having problems resolving the gravitational force into force down the slope - My first line of thinking was to draw in the normal reaction and resolve that such that the overall force = 12gtan5 - 15
however the solution book says the answer is 12gsin5 - I cannot work out how this is done

2. Jun 6, 2009

### Staff: Mentor

You need to know how to resolve forces into components. Read this: http://www.physicsclassroom.com/Class/vectors/u3l3e.cfm" [Broken]

Last edited by a moderator: May 4, 2017
3. Jun 6, 2009

### Vanagib

Many thanks, It's hit me now.