Remember the definition of work done.
Work done is force(F) times displacement(x)
∴ W = F.Δx
According to Newton's 2nd law of motion,
F = ma
∴ W = ma.Δx ---- (i)
Using the kinematical equation v²-u² = 2ax,
aΔx = (v²-u²)/2
Plug this value in (i),
∴W = m[

]
∴W =

Which is nothing but change in kinetic energy.
That is how kinetic energy is derived
Well, in order to figure out the answer is to divide until you figure out how many miles they went per second. If it takes 5 seconds to reach 50 miles per hour it took 10 seconds per every 10 miles meaning each mile took 1 second. (Not actually possible but the answer) So, If it finished a 100 mile trip in 2 hours it took an hour for 50 miles. If it took 1 hour for 50 miles divide 60/50 which gets you 1.2 so it took 1.2 miles per minute meaning the car went 120 miles per hour I believe. I hope this helps :)
Answer:
Workdone = 1250Nm
Explanation:
<u>Given the following data;</u>
Force, F = 500N
Distance, d = 2.5m
Workdone is given by the formula;
Substituting into the equation, we have
Workdone = 1250Nm
Therefore, the actual work done by the worker is 1250 Newton-meter.