A block of mass 12 kg starts from rest and

slides a distance of 8 m down an inclined
plane making an angle of 40◦
with the horizontal. The coefficient of sliding friction between block and plane is 0.4.
The acceleration of gravity is 9.8 m/s^2

What is the net force on the block along the
incline?

What is the speed of the block after sliding
8 m?

What would be its speed if friction were negligible?