Physics-Work and Power-Help Please? Thanks!?
Could someone help me with this problem. Please explain what equation I should use and how I go about solving it. I don't know how to do it. It would be greatly appreciated. Thanks!
1.) A 1500kg car accelerates uniformly from rest to 10m/s in 3 secs.
a.) What is the work done on the car in this time period?
b) What is the power delivered by the engine in this time period?
Thanks again! 10 Points Available!!!!
- Charles MLv 61 decade agoFavorite Answer
a. Calculate work. Work is the the amount of energy transferred by a force, done over a net distance.
F = ma
W = Fd, d is the distance or in this case since we can but don't want to calculate the distance
W = 1/2 * mv^2
Plug in the numbers:
W = 1/2 * 1500kg (10m/s)(10m/s)
Work = 75 kJ
b. Calculate the power. Power is the rate at which work is done, so this will be in units per second.
P = W / t
P = 75 kJ / 3s
P = 25 kW
- ukmudgalLv 61 decade ago
Mass of car = 1500 kg
Initial velocity = u = 0
Final velocity = v = 10m/s
time = t = 3 s
Work done on a body equals increases its kinetic energy
Initial kinetic energy =KEi=(1/2)mu^2=zero
Final kinetic energy =KEf=(1/2)mv^2=0.5*1500*( 10 )^2=75000 J
Increase in kinetic energy =KEf - KEi =75000 J
Work done on a body = increase in kinetic energy=75000 J
a)the work done on the car in 3 second is 75000 J
Power = work / time =75000 /3 =25000 watt = 25 kW
b) The power delivered by the engine in 3 second is 25000 W or 26 kW