Answer:
Part A
it would take 6 sec
it would take 3 sec
Explanation:
We are told that the power supplied to the wheel is constant which means that the sport car is gaining energy i.e
[tex]power \ \alpha \ energy[/tex]
Hence if power is constantly supplied energy constantly increase
From the formula of the Kinetic energy
[tex]KE = \frac{1}{2} mv^2[/tex]
we can see that as the speed doubles from 29 mph to 58 mph the energy needed is [tex]2^2[/tex] = 4 times of the energy from the formula
Also the time needed would also be 4 times because energy i directly proportional to time
Hence to reach 58mph the time that it would take is
= [tex]4* 1.5sec = 6sec[/tex]
We are told that the ground pushes the car with a constant force and
F = ma
this means that the acceleration is also constant
now from newtons law
v = u +at
Looking at it we see that final velocity is directly proportional with time
hence it would take twice the time to reach twice the final velocity
Time to reach 58mph = 3 s
since time to reach 29 mph([tex]\frac{1}{2} \ of \ [58mph][/tex]) =( [tex]\frac{1}{2} \ of \ 3sec[/tex] )1.5 s
