am confused. don't know what formula to use for this problem. A car traveling at a speed of 30.0m/s encounters an emergency and comes to a complete stop. How much time will it take for the car to stop if it decelerates at -4.0m/s?
T=(vf-vi)/a= (0-30)m/s/(-4.0)m/s then T=7.5s ...it is as simple as that.
ASK QUESTIUON
To solve this problem, you need to use the kinematic equation that relates the final velocity, initial velocity, acceleration, and time.
The formula you can use for this problem is:
v = u + at
Where:
v = final velocity
u = initial velocity
a = acceleration
t = time
In this case, the car starts with an initial velocity of 30.0m/s, and it decelerates at a rate of -4.0m/s. Since the car is decelerating, the acceleration should be negative.
Substituting the given values into the formula, we have:
0 = 30.0 - 4.0t
Now, let's solve for t.
Rearranging the equation, we get:
-4.0t = -30.0
Dividing both sides of the equation by -4.0, we have:
t = -30.0 / -4.0
Simplifying the division, we find:
t ≈ 7.5 seconds
Therefore, it will take approximately 7.5 seconds for the car to come to a complete stop when it decelerates at -4.0m/s.