Respuesta :
Answer:
W = 439998 J = 439.99 KJ
Explanation:
First, we will calculate the acceleration of the car by using the first equation of motion:
[tex]v_f = v_i + at\\\\a = \frac{v_f-v_i}{t}[/tex]
where,
a = acceleration = ?
vf = final speed = [tex]108(\frac{km}{h})(\frac{1000\ m}{1\ km})(\frac{1\ h}{3600\ s})[/tex] = 30 m/s
vi = initial speed = [tex]36(\frac{km}{h})(\frac{1000\ m}{1\ km})(\frac{1\ h}{3600\ s})[/tex] = 10 m/s
t = time = 30 s
Therefore,
[tex]a = \frac{30\ m/s - 10\ m/s}{30\ s}[/tex]
a = 0.67 m/s²
Now, we will calculate the force applied by the engine:
F = ma
where,
F = force = ?
m = mass = 1100 kg
Therefore,
F = (1100 kg)(0.67 m/s²)
F = 733.3 N
Now, we will calculate the distance covered by the car by using the second equation of motion:
[tex]s = v_it+\frac{1}{2}at^2\\\\s = (10\ m/s)(30\ s)+\frac{1}{2} (0.67\ m/s^2)(30\ s)^2[/tex]
s = 600 m
Now, the work done (W) by engine can be calculated as follows:
W = Fs
W = (733.3 N)(600 m)
W = 439998 J = 439.99 KJ