# mechanics M1 Alevel

Printable View

• Nov 20th 2012, 07:51 PM
abdulrehmanshah
mechanics M1 Alevel
A BODY OF MASS 5KG IS INITIALLY AT REST AT THE BOTTOM OF A ROUGH INCLINED PLANE OF LENGTH 6.3M THE PLANE IS INCLINED AT 30 DEGREES TO THE HORIZONTAL AND THE COEFFICIENT OF FRICTION BETWEEN THE BODY AND THE PLANE IS 0.3 a constant horizantal force of 60.6N is applied to the body causing it to accelerate up the plane find the time taken for the body to reach the top and its speed on arrival.
Answers 3s, 4.2ms^-1
My Attempt MA=60.6 - {(0.3*5gCos30)+(5gsin30)} but i stuck here i dont know where to start from help
• Nov 21st 2012, 07:54 AM
BobP
Re: mechanics M1 Alevel
If the applied force is horizontal then to get its component along the slope you need to multiply by cos30, and it will also make a contribution to the normal reaction and hence the force due to friction. What are you taking g to be equal to ?
• Nov 21st 2012, 08:41 AM
skeeter
Re: mechanics M1 Alevel
Quote:

Originally Posted by abdulrehmanshah
A BODY OF MASS 5KG IS INITIALLY AT REST AT THE BOTTOM OF A ROUGH INCLINED PLANE OF LENGTH 6.3M THE PLANE IS INCLINED AT 30 DEGREES TO THE HORIZONTAL AND THE COEFFICIENT OF FRICTION BETWEEN THE BODY AND THE PLANE IS 0.3 a constant horizantal force of 60.6N is applied to the body causing it to accelerate up the plane find the time taken for the body to reach the top and its speed on arrival.
Answers 3s, 4.2ms^-1
My Attempt MA=60.6 - {(0.3*5gCos30)+(5gsin30)} but i stuck here i dont know where to start from help

applied force component up the incline - weight component down the incline - friction force down the incline = net force

$F\cos{\theta} - mg\sin{\theta} - \mu(mg\cos{\theta} + F\sin{\theta}) = ma$