1. A block weighing 300. N is moved at constant speed over a horizontal surface by a force of 50. N applied parallel to the surface.
A) What is the coefficient of kinetic friction? (0.17)
B) What would be the acceleration of the block if k = 0? (1.6 m/s2)
I would appreciate it if the work was shown, so I can understand how you got the answer. Thank you.
Slowfinger
constant speed → no acceleration → zero net force (pulling force is in equilibrium with friction)
Friction force
Ffr = μk Fn
μk is coefficient of kinetic friction
Fn is normal force, Fn=300 N
Friction force is in equilibrium with F=50 N
Ffr = F
so
μk Fn = F
μk = F / Fn
μk = 50 / 300 = 0.17
If μk=0, there is no friction, Ffr=0
Net force equals F and it give block an acceleration
a = F/m = F g / Fn
(because Fn = m g)
a = 50 * 9.80 / 300 = 1.63 m/s^2