Please help me to solve this problem about
electic potential :
An electric car accelerates for 7.0 s by drawing energy from its 290-V battery pack. During this time, 1200 C of charge pass through the battery pack .
Find the minimum horsepower rating of the car.
Joules = Watt seconds = i V t = Q t = 1200*290 = 348000 Joules
Watts = Joules/second = 348000/7 = 49,714 Watts
I do not remember the conversion from Watts to hp
do this: Paste in the google search window
1hp in watts
then memorize that number
Then, even lazier, put in the google search window
49714 watts in hp
To find the minimum horsepower rating of the car, we need to calculate the power used by the car during the acceleration.
First, let's find the work done by the car during the acceleration. The work done (W) can be calculated using the formula:
W = q * ΔV
Where:
- W is the work done
- q is the charge passing through the battery pack
- ΔV is the change in electric potential
Given that 1200 C of charge (q) pass through the battery pack and the electric potential (ΔV) is 290 V, we can calculate the work done:
W = 1200 C * 290 V = 348,000 J
Since power (P) is defined as the rate at which work is done, we can find the power by dividing the work done by the time taken:
P = W / t
Where:
- P is the power
- W is the work done
- t is the time taken
Given that the car accelerates for 7.0 s, we can calculate the power:
P = 348,000 J / 7.0 s = 49,714 W
Now, to convert this power value into horsepower, we can use the conversion factor:
1 horsepower (hp) = 745.7 W
Therefore, the minimum horsepower rating of the car is:
49,714 W / 745.7 W/hp ≈ 66.7 hp
So, the minimum horsepower rating of the car is approximately 66.7 hp.