A car traveling at a speed of 30.0 m/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 -4.0 m/s2
?
v = 30.0 - 4.0 t
when is v=0?
To find the time it takes for the car to come to a complete stop, given its initial speed and deceleration, you can use the following formula:
t = (vf - vi) / a
Where:
t = time
vi = initial velocity/speed
vf = final velocity/speed (which is 0 as the car comes to a complete stop)
a = acceleration (negative in this case since it's decelerating)
Now, let's substitute the given values into the formula:
vi = 30.0 m/s
vf = 0 m/s
a = -4.0 m/s^2
t = (0 - 30.0) / (-4.0)
To simplify the equation, divide both the numerator and denominator by -4.0:
t = -30.0 / -4.0
The negative signs cancel out, resulting in:
t = 7.5 seconds
Therefore, it will take the car 7.5 seconds to come to a complete stop.