-- Accelerating at the rate of 8 m/s², Andy's speed after 30 seconds is
(8 m/s²) x (30.0 s) = 240 m/s .
-- His average speed during that time is
(1/2) (0 + 240 m/s) = 120 m/s .
-- In 30 sec at an average speed of 120 m/s, Andy will travel a distance of (120 m/s) x (30 sec) = 3,600 m
= 3.6 km .
"But how ? ! ?", you ask.
How in the world can Andy leave a stop light and then cover 3.6 km = 2.24 miles in the next 30 seconds ?
The answer is: His acceleration of 8 m/s², or about 0.82 G is what does it for him.
At that rate of acceleration ...
-- Andy achieves "Zero to 60 mph" in 3.35 seconds, and then he keeps accelerating.
-- He hits 100 mph in 5.59 seconds after jumping the light ... and then he keeps accelerating.
-- He hits 200 mph in 11.2 seconds after jumping the light ... and then he keeps accelerating.
-- After accelerating at 8 m/s² for 30 seconds, Andy and his car are moving at 537 miles per hour ! We really don't know whether he keeps accelerating, but we kind of doubt it.
A couple of observations in conclusion:
-- We can't actually calculate his displacement with the information given. Displacement is the distance and direction between the starting- and ending-points, and we're not told whether Andy maintains a straight line during this tense period, or is all over the road, adding great distance but not a lot of displacement.
-- It's also likely that sometime during this performance, he is pulled over to the side by an alert cop in a traffic-control helicopter, and never actually succeeds in accomplishing the given description.
Gamma rays have the highest energies, the shortest wavelengths, and the highest frequencies. Radio waves, on the other hand, have the lowest energies, longest wavelengths, and lowest frequencies of any type of EM radiation.
