Answer: 40.2 hp
Explanation:
The mass of the car is 2000kg.
in 21 seconds, it accelerates from 0m/s to 25m/s, so the average acceleration is:
a = (25m/s)/(21s) = 1.2 m/s^2
We know that force = mass*acceleration, then:
F = 2000kg*1.2m/s^2 = 2400N.
Now, the Power can be written as:
P = W/t where W is work = F*d (force per distance) and t is time.
then we have:
P = (F*d)/t and d/t is the average velocity, and we know the velocity v = 25m/s, so the average velocity will be (1/2)*25m/s = 12.5m/s
P = F*12.5m/s
and the force is F = 2400N
P = 2400 N*12.5m/s = 30,000 W
and we know that 1hp = 746 W
then, P = (30,000/746) hp = 40.2 hp
Answer:
[tex]P=40hp[/tex]
Explanation:
Hello,
In this cased, for the given velocities, we can compute the work done by the car as shown below, considering the kinetic energy only:
[tex]W=\frac{1}{2}m(v_f^2-v_0^2)[/tex]
Whereas the mass is 2000 kg, the final velocity is 25 m/s and the initial velocity is 0 m/s, therefore the work is:
[tex]W=\frac{1}{2}*2000kg*[(25\frac{m}{s})^2 -(0\frac{m}{s})^2]\\\\W=\frac{1}{2}*2000kg*625\frac{m^2}{s^2} \\\\W=6.25x10^5J[/tex]
Now, the power:
[tex]P=\frac{W}{t}=\frac{6.25x10^5}{21.0s}=29762W[/tex]
And in horsepower:
[tex]P=29762W*\frac{1hp}{746W} \\\\P=40hp[/tex]
Best regards.
