Answer:
-0.18 N
Explanation:
The motion of the piece of rubber is a uniformly accelerated motion, so we can find its acceleration using the suvat equation:
[tex]v^2-u^2=2as[/tex]
where:
v = 10 m/s is the final speed
u = 20 m/s is the initial speed
a is the acceleration
s = 102 m is the distance covered
Solving for a,
[tex]a=\frac{v^2-u^2}{2s}=\frac{10^2-20^2}{2(102)}=-1.47 m/s^2[/tex]
The net force acting on the piece of rubber is the force of friction; according to Newton's second law of motion, the force is equal to the product of mass (m) and acceleration (a):
[tex]F=ma[/tex]
Here we have
m = 0.125 kg is the mass
Therefore, the force of friction is:
[tex]F=ma=(0.125)(-1.47)=-0.18 N[/tex]
And the negative sign means the direction of the force is opposite to the direction of motion.
