Homework for XI / group B / Vidyarthi /Friday?28-09-2018

Q1.  A force of 200 N is applied to a block of mass 20 kg on an inclined plane at 37 º with the horizontal .

(i)  What will be the acceleration of the block in downward direction ?

(II) How much force is required to move it in up along the plane ?

Q2.  The coefficient of friction for a block of mass 10 kg and a surface is  0.3 .  Find the force of friction and the acceleration of the block if the applied force is 10 N , 30 N , 50 N and 0 N .

Q3. Explain why

(i) rolling friction helps in motion

(ii) static friction is a self adjusting force

Q4. State the laws of friction

Q5. Define the following terms

Sliding friction , limiting friction , angle of friction , coefficient of kinetic friction , angle of repose .