Question

An electric car is being designed to have an average power output of 4,600 W for 2 h before needing to be recharged. (Assume there is no wasted energy.)

How much energy would be stored in the charged batteries? =J
The batteries operate on 80 V. What would the current be when they are operating at 4,600 W? =A
To be able to recharge the batteries in 1 h, how much power would have to be supplied to them? =W

Answer 1

a)3312 x 10⁴ J

b)I = 57.5 A

c)9200 W

Step-by-step explanation:

Given that

P =4600 W

Time t= 2 h = 2 x 3600 s= 7200 s

We know that

1 W = 1 J/s

a)

Energy stored in the battery = P .t

=4600 x 7200 J

=3312 x 10⁴ J

b)

We know that power P given as

P = V .I

V=Voltage ,I =Current

4600 = 80 x I

I = 57.5 A

c)

The energy supplied = 4600 x 2 = 9200 W