View Full Version : Newton's laws of motions
silver11
Oct 25, 2011, 10:12 PM
A 3kg block starts from rest at the top of a 30 degrees incline and slides 2m down the incline in 1.50 s. Find a) Acceleration of the block, b) Coefficient of kinetic friction between the block and the incline, c)The frictional force acting on the block and , d) The speed of the block.
Unknown008
Oct 26, 2011, 03:10 AM
a) Use your kinematics formulae to get the acceleration (s = ut +\frac12 at^2)
b) Find the net force acting on the block using F = ma.
Then, use F_{net} = F_g - F_f
Where Ff is the frictional force. Fg is obtained by getting the weight component of the block down the slope.
Then, to get the coefficient of friction, use F_f = \mu R
Where R is the normal force of the plane on the block and mu is the coefficient of friction.
c) Simply evaluate F_f = \mu R
d) The speed of the block at 2m down the slope I suppose? Use the acceleration you got in a) and use v = u + at