Starting from rest, a car accelerates at a rate of 4.2 m/s2 for a time of 5 seconds, what is its velocity at the end of this time?

initial velocity=0m/s

acceleration=4.2m/s^2

time taken =5s

then final velocity

v=u+at

or, v=0+4.2*5

so final velocity is 21m/s

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

a) electrical > light, sound, and thermal< < < <

) the mechanical energy of the firefighter moving.< < < < a) electrical > light, sound, and thermal< < < <

c) both a and b.