Question

8. A 30 kg object, initially at rest, slides 10 m down a 20° ramp at 1. 8 m/s2. a. How long does it take the object to get to the bottom of the ramp? b. what is the coefficient of friction between the object and the ramp?

Answer 1

here,

8)

mass of object , m = 30 kg

s = 10 m

theta = 20 degree

accelration , a = 1.8 m/s^2

a)

let the time taken be t

s = v0 * t + 0.5 * a * t^2

10 = 0 + 0.5 * 1.8 * t^2

solving for t

t = 3.33 s

the time taken is 3.33 s

b)

let the coefficient of friction be uk

accelration , a = net force /effective mass

a = ( m * g * sin(theta) - uk * m * g * cos(theta))/m

1.8 = 9.81 * (sin(20) - uk * cos(20))

solving for uk

uk = 0.17