Answer:
(a) To find the velocity at time t, we need to integrate the acceleration function with respect to time.
∫a(t)dt = ∫(2t + 4)dt = t^2 + 4t + C
We can find the constant of integration by using the initial velocity, v(0) = -5.
v(0) = -5 = C
So the velocity function is:
v(t) = t^2 + 4t - 5
Plugging in t=3, we get:
v(3) = 3^2 + 4(3) - 5 = 16 m/s
Therefore, the velocity at time t is 16 m/s.
(b) To find the distance traveled during the given time interval, we need to integrate the velocity function with respect to time.
∫v(t)dt = ∫(t^2 + 4t - 5)dt = (1/3)t^3 + 2t^2 - 5t + C
We can find the constant of integration by using the initial position, x(0) = 0.
x(0) = 0 = C
So the position function is:
x(t) = (1/3)t^3 + 2t^2 - 5t
Plugging in t=3 and t=0, we get:
x(3) = (1/3)(3)^3 + 2(3)^2 - 5(3) = 9 m
x(0) = 0
Therefore, the distance traveled during the given time interval is 9 m.