sports cars z image
Yves
A sports car accelerates from zero to 30 mph in 1.5 seconds. How long does it take for it to accelerate from zero to 60 mph, assuming the power of the engine to be independent of velocity and neglecting friction?
A) 2 seconds
B) 3 seconds
C) 6 seconds
D) 12 Seconds
explain.
Answer
With constant power, the force has to be inversely proportional to velocity (F x v = P) . So this is a little counterintuitive if you try to attack from the acceleration point of view...
You should take the approach of energy. See what is the ratio of kinetic energy at speed of 30 KMPH to speed of 60 KMPH . Ki netic energy is proportional to square of speed... , so you would get a certain ratio.
Since the power is constant, the time taken will be proportional to the kinetic energy. So, if the ratio of kinetic energy at 60 KMPH is to kinetic energy at 30 KMPH is N:1, the time taken will also have a ratio of N:1.
I don't want to give you the answer, just give you the principle to use, so you can work it out easily.
Hope it helps you, and you vote for the answer.
With constant power, the force has to be inversely proportional to velocity (F x v = P) . So this is a little counterintuitive if you try to attack from the acceleration point of view...
You should take the approach of energy. See what is the ratio of kinetic energy at speed of 30 KMPH to speed of 60 KMPH . Ki netic energy is proportional to square of speed... , so you would get a certain ratio.
Since the power is constant, the time taken will be proportional to the kinetic energy. So, if the ratio of kinetic energy at 60 KMPH is to kinetic energy at 30 KMPH is N:1, the time taken will also have a ratio of N:1.
I don't want to give you the answer, just give you the principle to use, so you can work it out easily.
Hope it helps you, and you vote for the answer.
Can you name some cars that have turbo engines instead of supercharged engines?
tatethegre
Also, can you name me as many four cylinder sports cars as you can. I know a few right off. The Celica GT-S, Subaru Impreza WRX-STI, Lotus Exige S240, and I believe the Honda S2000 is another one. Anyway, can you name as many four cylinder sportscars as possible?
Answer
Sticking to cars with road going versions:
Turbos:
Porsche 930, 931, 934, 951, 965, 968 Turbo, 993 Turbo, 996 Turbo, 997 Turbo
Ferrari 288GTO, F40
Lotus Espirit Turbo, Elise GT1, Europa S
Ford Focus RS
Subaru WRX, STI
BMW 2002 Turbo
Mini Cooper S (later models)
Mitshubishi Evo, 3000GT, Eclipse Turbo
Pontiac Soltice
Vauxhall VX220
Alfa Romeo MiTo, GT
Lancia Stratos
Mazda RX7 Turbo
Nissan 300ZX Tubro, Skyline R32-34, GT-R
VW GTi, R32
Four Cylinders:
Porsche 356, 550, 904, 912, 914, 924, 931, 944, 951, 968
Ferrari 500TR
Lotus 7, Eclat, Espirit, Europa, Exige, Elan, Elise
Honda S2000
Ford Focus RS
Subaru RS, WRX, STI
BMW E30 M3, 2002, Z3, Z4
Mini Cooper, Cooper S
Mitshubishi Eclipse, Evo
Datsun Fairlady (pre Z)
MG Midget, B
Pontiac Soltice, Fiero
Vauxhall VX220
Fiat Spyder, X/19
Alfa Romeo MiTo, 147, 149, 159, Spider, GT, GTA, Giulia TZ
Renault Alpine A110
VW GTi, R32
And so on and so on... there are ALOT of cars that fall into these catagories. These are what I can come up with given a little thought.
Sticking to cars with road going versions:
Turbos:
Porsche 930, 931, 934, 951, 965, 968 Turbo, 993 Turbo, 996 Turbo, 997 Turbo
Ferrari 288GTO, F40
Lotus Espirit Turbo, Elise GT1, Europa S
Ford Focus RS
Subaru WRX, STI
BMW 2002 Turbo
Mini Cooper S (later models)
Mitshubishi Evo, 3000GT, Eclipse Turbo
Pontiac Soltice
Vauxhall VX220
Alfa Romeo MiTo, GT
Lancia Stratos
Mazda RX7 Turbo
Nissan 300ZX Tubro, Skyline R32-34, GT-R
VW GTi, R32
Four Cylinders:
Porsche 356, 550, 904, 912, 914, 924, 931, 944, 951, 968
Ferrari 500TR
Lotus 7, Eclat, Espirit, Europa, Exige, Elan, Elise
Honda S2000
Ford Focus RS
Subaru RS, WRX, STI
BMW E30 M3, 2002, Z3, Z4
Mini Cooper, Cooper S
Mitshubishi Eclipse, Evo
Datsun Fairlady (pre Z)
MG Midget, B
Pontiac Soltice, Fiero
Vauxhall VX220
Fiat Spyder, X/19
Alfa Romeo MiTo, 147, 149, 159, Spider, GT, GTA, Giulia TZ
Renault Alpine A110
VW GTi, R32
And so on and so on... there are ALOT of cars that fall into these catagories. These are what I can come up with given a little thought.
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