One runner in a relay race has a 1.50 s lead and is running at a constant speed of 3.25 m/s. the runner has 30.0 m to run before reaching the end of the track. a second runner moves in the same direction as the leader. what constant speed must the second runner maintain in order to catch up to the leader at the end of the race?

3.88m/s

Explanation:

The first runner has a 1.5s lead, multiply it by the constant speed (1.5 x 3.25) this equates to 4.875 metres.

4.875 metres is the distance the first runner has already covered.

Subtract this from the 30metres left to run, leaves = 25.125 metres.

If you divide 25.125 by 3.25 seconds which is constant speed of the first runner you will get the time in which the first runner finished the race.

25.125 / 3.25 = 7.73 seconds.

If you divide 30metres (because the second runner doesn't have a lead same as the first runner) by 7.73 seconds, you get 3.88.

The second runner must move with a speed of 3.88m/s in order to catch up the leader at the end of the race.

electrical potential energy =0.072 j

explanation:

electrical potential energy is given by

u= q δv

q= charge=6 c

δv= potential difference and is given by

δv= e d

e= electric field

d= distance=5 mm=0.005 m

δv=2.4 (0.005)=0.012 v

now electric potential energy= u= q δv

u=6 (0.012)

u=0.072 j