(a) To find the time taken to reach a speed of 2.00 m/s, we can use the equation:
v = u + at
Where:
v = final velocity = 2.00 m/s
u = initial velocity = 0 (since she starts from rest)
a = acceleration = 1.40 m/s²
t = time taken (unknown)
Rearranging the equation, we get:
t = (v - u) / a
t = (2.00 - 0) / 1.40
t = 2.00 / 1.40
t ≈ 1.43 seconds
So, it takes her approximately 1.43 seconds to reach a speed of 2.00 m/s.
(b) To find her acceleration when she brakes to a stop, we can use the equation:
v = u + at
Where:
v = final velocity = 0 (since she comes to a stop)
u = initial velocity = 2.00 m/s
a = acceleration (unknown)
t = time taken = 0.800 s
Rearranging the equation, we get:
a = (v - u) / t
a = (0 - 2.00) / 0.800
a = -2.00 / 0.800
a ≈ -2.50 m/s²
Her acceleration when braking to a stop is approximately -2.50 m/s² (negative because it is deceleration).
A commuter backs her car out of her garage with an acceleration of 1.40m/s². (a) how long does it take her to reach a speed of 2.00m/s? (b) if she than brakes to a stop in 0.800s, what is her acceleration?
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