Answer starting at sea level, a submarine descended at a constant rate to a depth of −45−45 mile relative to sea level in 3 minutes.

what was the submarine's depth relative to sea level after the first minute?

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.

answer:

c. the third graph