C is the awnser I believe correct me if I’m wrong
The least common denomonator is 60
Step-by-step explanation:
80 times 2 is 160
Therefore, 100 times 2 is 200
You multiply the denominator and numerator by the same number.
When the direction is reversed velocity = 0
v = ds/dt = 6t^2 - 42t + 60 = 0
t^2 - 7t + 10 = 0
(t - 5)(t - 2) = 0
t = 2 s and 5 s which are the times when the direction is reversed
Position at t = 2 = 2(2)^3 - 21(2)^2 +60(2) + 3 = 55 feet
at t = 5 position = 28 feet
Acceleration = dv/dt = 12t - 42
At t = 2 acceleration = -18 ft s-2
At t = 5 ............... = 18 ft s-2

Scientific notation for above value is ~