In 10 seconds a car accelerates 3m/s^2 to 90m/s. How fast was the car going before it accelerated?
To find the initial speed of the car before it accelerated, we can use the equation of motion:
v = u + at
where:
v = final velocity = 90 m/s
u = initial velocity (unknown)
a = acceleration = 3 m/s^2
t = time taken for acceleration = 10 seconds
Rearranging the equation to solve for u:
u = v - at
Substituting the given values:
u = 90 m/s - (3 m/s^2)(10 s)
u = 90 m/s - 30 m/s
u = 60 m/s
Therefore, the car was going 60 m/s before it accelerated.
To find the initial velocity of the car before it accelerated, you can use the equation of motion:
Final velocity (v) = Initial velocity (u) + Acceleration (a) x Time (t)
We are given:
Final velocity (v) = 90 m/s
Acceleration (a) = 3 m/s^2
Time (t) = 10 seconds
Rearranging the equation and plugging in the given values, we can solve for the initial velocity (u):
u = v - a x t
u = 90 m/s - 3 m/s^2 x 10 s
u = 90 m/s - 30 m/s
u = 60 m/s
Therefore, the car was going 60 m/s before it accelerated.