The car is 1000 kg and can travel from 0 m/s to 50 m/s in 10 s. Thanks for any insight.
If you're using the formula work = change in kinetic energy, don't you have to add both the mass of the car and the mass of the batteries as well for m in 1/2m(v1-vo)2?How many car batteries are needed (rated at 10 V and 100 A) with a mass of 10 kg each to accelerate a car...?assuming the mass of the car includes that of the batteries. It doesn't say otherwise.
KE = 陆mV虏
KE = 陆(1000)(50)虏 = 1.25 MJ
power = 1.25 MJ / 10s = 125 kW
Batteries are not rated in amps, but in amp-hours. Skipping that, each battery can deliver 1000 watts or 1 kW, so you need 125 batteries.
if you assume the weight of the car does not include the batteries, then N = number of batteries.
1000w x N = 陆(1000+10N)(50)虏 / 10s
10000N = 2500(500+5N)
10000N = 1.25e6+12500N
?500 = 1.25e6 N
N is negative, which means this doesn't work.
With one battery alone and t unknown
1000 = 陆(10)(50)虏 / t
t = 12500 / 1000 = 12.5 sec
in other words, the power of one battery with no other weight cannot accelerate to the desired speed in the desired 10 seconds.
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