please show working for these questions please e. 40J c. 2J d. 20J 21. How much
ID: 1782510 • Letter: P
Question
please show working for these questions please
e. 40J c. 2J d. 20J 21. How much work is done on a 20-N crate that you lift 2 m a. 0J 22 How much power is expended if you lift a 60 N crate 10 meters in 1 second? c. 600 w c. 10 W d. 60 W 23. Supose a moving car has 300 J of kinctic energy. If the car's speed doubles, how much kinetic energy will it then have? a. 1000J b. 1500 J c. 3000J d. 6000 J e. 12,000J 24. It takes 80 J to push a large box 8 m across a floor. Assuming the push is in the same direction as the move, what is the magnitude of the force on the box? a. 8 N b. 10 N c. 80 N d. 640 N e. none of the above 25. If Kelly the skater's speed increases so he has three times the momentum, then his kinetic energy increases by a one third times. b. three times. c. nine times. d. none of the above (KE remains the same).Explanation / Answer
21.
Work done
W=Fd =20*2
W=40 J
22.
Work done
W=60*10=600 J
Power
P=W/t =600/1 ==600 watts
23.
Kinetic energy is given by
K=(1/2)mV2
=>K2/K1=(V2/V1)
Given V2=2V1
K2=3000*22=12000 J
24.
Force
F=W/d =80/8
F=10 N
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.