Mechanics M1 question. Motion of a block on a slope

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SUMMARY

The discussion centers on calculating the acceleration of a block sliding down a slope inclined at 5 degrees with a mass of 12 kg and an initial speed of 1.5 m/s. The block experiences a constant resistance of 15 N. The correct approach to find the resultant force involves resolving the gravitational force into components, specifically using the equation F = 12g sin(5°) - 15 N. This leads to the calculation of acceleration and subsequently the time and distance the block slides before coming to rest.

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Homework Statement


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?


Homework Equations


F=ma


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
 
Physics news on Phys.org
You need to know how to resolve forces into components. Read this: http://www.physicsclassroom.com/Class/vectors/u3l3e.cfm"
 
Last edited by a moderator:
Many thanks, It's hit me now.
 

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