Question

A horizontal force FFaa���⃗ of magnitude 20.0 N is applied to a 3.00 kg psychology book as the book slides a distance d = 0.500 m up a frictionless ramp at angle θ = 30.0°. (a) During the displacement, what is the net work done on the book? (b) If the book has zero kinetic energy at the start of the displacement, what is its speed at the end of the displacement?

Answer 1

Answer:

(a) W = 8.66 J

(b) Velocity = 2.40 m/s

Explanation:

(a) Work done is given as the product of force and displacement. That is:

W = F * d * cos(A)

Where F = force applied

d = distance moved

A = angle of ramp

Therefore, work done is:

W = 20 * 0.5 * cos30

W = 8.66 J

(b) Work done is equal to change in Kinetic energy. Since the initial kinetic energy is zero:

W = KE(final)

W = ½ * m * v²

Where v = final velocity

=> 8.66 = ½ * 3 * v²

v² = 5.773

v² = 2.40 m/s