Mark leaves uncc at 1: 00 p. m. going 50mph and alex leaves uncc at 3: 00 p. m. going 70mph on the same highway in the same direction. at what time does alex catch up with mark?

Mark has a 100-mile head start (2 hours at 50 miles per hour). Alex is closing at the rate of 70 - 50 = 20 miles per hour. It will take him

... (100 mi)/(20 mi/h) = 5 h

to catch up.

Alex catches up with Mark at 8:00 pm.

They will meet up 350 miles from uncc.

constant acceleration- a

constant velocity- c

no velocity or acceleration- b

explanation:

for body moving with a constant acceleration, the rate of change of displacement changes over time. this is proven by the increasing gradient of the curve (a) against time.

a body that is moving at constant velocity covers equal distances over equal periods of time, thus the straight line with a constant gradient c.

a stationary body   covers no displacement as time elapses. thus the flat line with   zero gradient.