University:
Eastern Kentucky University
Course:
PHY 131 | College Physics I
Academic year:

2021
Views:

234

Pages:

2
Author:

kundgetanufv

Which has greater kinetic energy? a car of half the mass traveling at 60 km/hr A block of ice sliding down an incline has half its maximum kinetic energy halfway down. A motorcycle moving at 50 km/h skids 10 m with locked brakes. How far will it skid with locked brakes when traveling at 150 km/h? 90 m Two identical arrows, one with twice the kinetic energy of the other, are fired into a bale of hay. Compared with penetration of the slow arrow, the faster arrow penetrates twice as far. A 2-kg ball is held 4 m above the ground. Relative to the ground its potential energy is 80 J. The amount of work done on a heavy box carried by Nellie across a room at a constant speed is none. The power required to exert 4-N force over 3 meters in 2 seconds is 6 W. A toy elevator is raised from the ground floor to the second floor in 20 seconds. The power needed using 1000 J of work, is 50 W. A moving object has all of these Upgrade to remove ads Only $2.99/month A ball rolling down an incline has its maximum potential energy at the top. A 2500-N pile-driver ram falls 10 m and drives a post 0.1 m into the ground. The average impact force on the ram is 250,000 N. . The work you do when pushing a shopping cart a given distance while applying twice as much force is twice as much Which requires the most amount of work by the brakes of a car? slowing down from 100 km/h to 70 km/h If you do work on a skateboard loaded with friends in one-third the usual time, you expend three times the usual power. The power expended doing 100 J of work in 50 s is 2 W. A melon is tossed straight upward with 100 J of kinetic energy. If air resistance is negligible the melon will return to its initial level with a kinetic energy of 100 J. A hydraulic press has its input piston depressed 20 centimeters while the output piston is raised 1 centimeter. A 1-newton input can lift a load of 20 N. A machine puts out 100 watts of power for every 1000 watts put into it. The efficiency of the machine is 10%. When Joshua brakes his speeding bicycle to a stop, kinetic energy is transformed to heat Upgrade to remove ads Only $2.99/month A roller skate at rest may have energy A circus diver drops from a high pole into water far below. When he is halfway down all of the above Both a 50-kg sack is lifted 2 meters from the ground and a 25-kg sack is lifted 4 meters in the same time. The power expended in raising the 50-kg sack is the same