Answer:
u = 2.36 m/s
Explanation:
Parameters given:
Mass of stone = 20kg
Distance moved before coming to rest = 27.9m
Frictional force = 2.0N
We can first find the acceleration of the stone by using the equation for frictional force:
F = -ma
Where m = mass of the object
a = acceleration
The negative sign denotes that the Frictional force acts opposite the motion of the stone.
=> 2.0 = -20*a
a = - 2.0/20
a = - 0.1m/s²
Using one of the equations of motion, we have that:
v² = u² + 2as
Where v = final velocity
u = initial velocity
s = distance moved.
In this case, v = 0m/s because the object comes to rest.
=> 0 = u² + (2 * - 0.1 * 27.9)
0 = u² - 5.58
u² = 5.58
u = √(5.58)
u = 2.36 m/s
The initial velocity of the stone is 2.36m/s
