Answer:
Explanation:
The sum of the pore along the plane is expressed according to Newton's law
Fn-Ff = ma
Fn is the moving force
Ff = nR = frictional force
m is the Mass
a is the acceleration
Substitute the given values
Fn - nR = ma
Fn - tan31°(mgcostheta) =3.9(9.8)
Fn - tan31(3.9(9.8)cos31) = 3.9(9.8)
Fn - tan31(38.22cos31)= 38.22
Fn - 32.76tan31 = 38.22
Fn-19.68 = 38.22
Fn = 38.22+19.68.
Fn = 57.90N
Hence Fn (moving force) of the inclined block is 57.90
Answer:
4 blocks west is final displacement. So 4 blocks per hour
Answer:

Explanation:
m = Mass of person = 70 kg
c = Specific heat of human body = 
= Change in temperature
Time taken is 1 hour
Heat is given by

The rise in temperature is 
I think it is this because compression stroke it needs to be compressed then open up when started.
Answer:
0 m/s
Explanation:
velocity= change in displacement/ time
at rest, the ball does not travel any distance
0/ t
=0