Question

2 kg
Use 10 m/s2 for g

Answer 1

See below

Step-by-step explanation:

At point A the PE = mgh = 2 * 10 * 1 = 20 J

at point B, all of the PE , 20 J , is converted to Kinetic Energy

KE = 1/2 m v^2

20 = 1/2 (2)(v^2 )

20 = v^2 v = sqrt 20 = 4.47 m/s

for the friction part

vf = vo t + 1/2 a t^2 vf = final velocity = 0 (stopped)

vo = original velocity = 4.47 m/s

a = -1 m/s^2

0 = 4.47 t + 1/2 (-1) t^2

- .5t^2 + 4.47 t = 0

t ( -.5t+ 4.47) = 0 shows t = 4.47/.5 = 8.9 seconds