Answer:
1. 1800 lb ft, 5.27 J
2. 905
Explanation:
1. Work is the change in energy.
W = mgh
W = (120 lb) (15 ft)
W = 1800 lb ft
W = mgh
W = (0.250 kg) (9.8 m/s²) (2.15 m)
W = 5.27 J
2. The IMA (ideal mechanical advantage) of a screw is the circumference of the screw divided by the pitch.
IMA = 2πr / p
The IMA of a handle (lever) is the circumference of the handle divided by the circumference of the screw.
IMA = 2πR / 2πr
The total IMA is the product:
IMA = (2πR / 2πr) (2πr / p)
IMA = 2πR / p
IMA = 2π (36) / (0.25)
IMA = 905
