How long does it take a car to change it velocity from 15m/s if it accelerarate uniformly at 5m/s square?
As far as I understand the car gets 5m/s faster with every second. The first second it's traveling at 5m/s. It increases by 5m/s again at the 2nd second. It is now traveling 10m/s. By the third second it increases again by 5m/s.
vfinal=vinitial+at
you have given vinitial, acceleration. You want the time t. So what final velocity are you aiming for, vfinal?
To find the time it takes for a car to change its velocity, we can use the equation of motion:
v = u + at
Where:
v = final velocity
u = initial velocity
a = acceleration
t = time
In this case, the initial velocity (u) is 15 m/s, the acceleration (a) is 5 m/s^2, and we need to find the time (t) it takes for the car to change its velocity.
Rearranging the equation, we have:
t = (v - u) / a
Substituting the given values, we have:
t = (0 - 15) / 5
Simplifying the equation:
t = -15 / 5
t = -3 seconds
However, it is important to note that time cannot be negative. Therefore, we can conclude that the car will take 3 seconds to change its velocity from 15 m/s to 0 m/s (assuming it decelerates uniformly at 5 m/s^2).