Static friction is the friction that exists between two or more solids that are not moving with a relative speed. To calculate the static friction coefficient we use the formula Fs=us × n where Fs is the static friction , us is the coefficient of static friction and the n is the normal force.
thus the coefficient of static friction will be 5 N÷ 25 N = 0.2
Hence 0.2 is the coefficient of static friction
Your weight #sorryfortheweight
Using the equation v(average)=x traveled/time
v = 100/2.5
You get 40 kilometers per hour
Hope this helped!
