Answer:
<h2>a) Average velocity = 278 units</h2><h2>b)
Instantaneous velocity at t = 7 seconds is 148 units</h2>
Step-by-step explanation:
a) Average velocity is the ratio of displacement to time.
We have
s(t) = t³ + t
t is in between 7 and 12
s(7) = 7³ + 7 = 350
s(12) = 12³ + 12 = 1740
Displacement = 1740 - 350 = 1390
Time = 12 - 7 = 5
Displacement = Average velocity x time
1390 = Average velocity x 5
Average velocity = 278 units
b) s(t) = t³ + t
Differentiating
v(t) = 3t² + 1
At t = 7
v(t) = 3 x 7² + 1 = 148 units
Instantaneous velocity at t = 7 seconds is 148 units
