a 100 W electric motor has an efficiency of 68%, how long will it take to lift a 40kg object to a height of 8m?

Q: A girl on skateboard (total mass of 56.1 kg) is moving at 14.1 m/s at the bottom of a long ramp. The…

A: Mass of the girl M=56.1 kg Initial speed u=14 m/s Final speed v=0 Angle of inclination θ=19.490…

Q: How much work can a 120 W motor do in 3.0 seconds? (120 W is the power of the motor.) Your answer:…

A: Power of the motor, P=120 wTime taken by the motor for working, t=3.0 sWork done by the motor…

Q: The potential energy of a girder, after being lifted to the top of a building, is 5.17 × 10⁵ ft lb.…

A:

Q: 27. How much power is required to do 18O J of work in 2.4 s?* O 432 J O 432 W O 75 J O 75 W

A:

Q: 7. An electric motor with an efficiency of 80% has a power output of 4.00 horsepower. The power…

A: Given, Output power = 4 horsepower. Efficiency = 80% Motor runs for = 3 hour Charges = $0.15 per kWH…

Q: A 3.13 kg object is dropped, from rest, from a height of 11.7 m above the ground. Assuming…

A: The required expression for the kinetic energy,

Q: A force of 16 lb is required to hold a spring stretched 2 in. beyond its natural length. How much…

A: Given data: Stretching force, F=16 lb Stretched distance, x=2 inch

Q: A water fountain uses 125 Watts of power each hour. It is run 24 hours each day for 7 days. If…

A: The formula for the amount of energy consumed by the fountain is:

Q: A man pushes a lawn mower on a level lawn with a force of 185 N. If 48% of the force is directed…

A:

Q: A 9.55 kg object is initially traveling at 24.8 m/s. During the next 185 seconds – 263 J of total…

A: According to the work energy theorem,

Q: A garage door has two springs, one on each side of the door. A force of 20 pounds is required to…

A: Given data *The given force is F = 20 pounds *The spring stretches is ∆x=2 feet *Each spring…

Q: A man pushes a lawn mower on a level lawn with a force of 187 N. If 43% of this force is directed…

A: Work done  W = Force * displacement Force must be in direction of displacement.

Q: How much potential energy does a 28.81 kg box have at a height of 7.46 m? Round your answer to 2…

A: Given thatm=28.81 kgh=7.46 mpotential energy is given by, U=mghwhere m is massg is acceleration due…

Q: An object is placed to a shelf from the ground which is 1.8 m higher. find out how much work is done…

A: