a car starts from rest and travels for 4.2 s with a uniform deceleration of 1.8m/s^2. what is the final velocity of the car?
if it starts at zero, and deaccelerates?
if you are stopped, then slow down?
To find the final velocity of the car, we need to use the equation of motion that relates acceleration, time, initial velocity, and final velocity:
v = u + at
where:
v = final velocity
u = initial velocity (which is 0 in this case, since the car starts from rest)
a = acceleration (which is -1.8 m/s^2, since it is a deceleration)
t = time (which is given as 4.2 seconds)
Substituting the given values into the equation, we have:
v = 0 + (-1.8) * 4.2
Simplifying the equation, we get:
v = -7.56 m/s
Therefore, the final velocity of the car is -7.56 m/s, which means it is moving in the opposite direction of its initial motion (i.e., decelerating).