Stuck with part ii) and iii), I think I have done i) correctly but if not please tell if I'm wrong and why
With ii) and iii), I keep getting expressions and not actual values for the magnitude of limiting friction, coefficient of friction etc. Is there anything I'm missing here?
The force up the slope is equal to the force down the slope. So the component of the weight of the block down the slope is equal to the friction force. Using that force, you can then work out the co efficient of friction in the next part.
The force up the slope is equal to the force down the slope. So the component of the weight of the block down the slope is equal to the friction force. Using that force, you can then work out the co efficient of friction in the next part.
How do you know that the cube is going down the slope at a steady speed?
How do you know that the cube is going down the slope at a steady speed?
It is not moving at a steady speed. It is not moving at all. If there is a frictional force then that means there is an equal and opposite force against friction. There is no resultant because it is not moving so they are equal
It is not moving at a steady speed. It is not moving at all. If there is a frictional force then that means there is an equal and opposite force against friction. There is no resultant because it is not moving so they are equal
Ahh so simply put it the cube is in equilibrium since it's stationary (i.e. zero resultant force). And equal and opposite forces which are parallel to the slope are component of cube weight down the slope to frictional force between the cube and steel sheet up the slope?
That means the frictional force is equal to mgsin(theta) = 1*9.8*sin(40) = 6.3N and coefficient of friction is 'mgsin(theta)/mgcos(theta) = tan(theta) = tan(40) = 0.84