If the distance covered by an object in time t is given by s(t)=2t^2+3t , where s(t) is in meters and t is in seconds, what is the average velocity over the interval from 2 seconds to 4 seconds?
answers:
a) 15m/s
b) 14m/s
c) 13m/s
d) 12m/s
e) 11m/s

a) 15 m/s.

Step-by-step explanation:

s(t) = 2t^2+ 3t

Distance at 2 seconds =  s(2) = 2(2)^2 + 3(2) =  14 m.

Distance at 4 seconds =  s(4) = 2(4)^2 + 3(4) =  44 m.

Average velocity = distance travelled from t = 2 until t = 4 /  time

= (44 - 14) / 4 -2

= 30/2

= 15 m / s.

b.an increase in a causes b to decrease