Question:
A car is traveling along a straight road. The velocity of the car is given by the equation:
v(t) = 3t + 2
Where v(t) is the velocity of the car in meters per second (m/s) and t is the time in seconds (s). Determine:
a) The initial velocity of the car.
b) The average velocity of the car over the time interval from t = 1s to t = 4s.
c) The acceleration of the car.
Answer:
a) The initial velocity of the car can be determined by evaluating the velocity equation at t = 0.
v(0) = 3(0) + 2 = 2 m/s
Therefore, the initial velocity of the car is 2 m/s.
b) The average velocity over a time interval is given by the change in displacement divided by the change in time. In this case, we need to calculate the displacement of the car between t = 1s and t = 4s.
The displacement can be obtained by integrating the velocity equation over the given time interval:
d(t) = ∫ v(t) dt = ∫ (3t + 2) dt
d(t) = (3/2)t^2 + 2t + C
Evaluating the integral limits:
d(4) - d(1) = (3/2)(4)^2 + 2(4) - [(3/2)(1)^2 + 2(1)]
d(4) - d(1) = 24 - 4 = 20 m
The change in displacement is 20 m, and the change in time is 4s - 1s = 3s.
Therefore, the average velocity is:
v_avg = (20 m) / (3 s) = 6.67 m/s
So, the average velocity of the car over the time interval from t = 1s to t = 4s is 6.67 m/s.
c) The acceleration can be obtained by taking the derivative of the velocity equation with respect to time:
a(t) = d(v(t))/dt = d(3t + 2)/dt = 3
Therefore, the acceleration of the car is 3 m/s².