To determine if a car traveling at 45 m/h slows down at a constant acceleration of 0.5 m/s², we need to convert the car's initial velocity from miles per hour (m/h) to meters per second (m/s).
1 mile = 1609.34 meters 1 hour = 3600 seconds
Therefore, 45 m/h is equivalent to: (45 m/h) * (1609.34 m/1 mile) * (1 hour/3600 seconds) ≈ 20.12 m/s
Now, let's use the equations of motion to analyze the car's deceleration:
v = u + at
Here: v = final velocity = 0 m/s (since the car is slowing down) u = initial velocity = 20.12 m/s a = acceleration = -0.5 m/s² (negative since it's deceleration) t = time taken to decelerate (unknown)
We can rearrange the equation to solve for time:
t = (v - u) / a
Plugging in the values:
t = (0 - 20.12) / (-0.5) t ≈ 40.24 seconds
Therefore, if the car experiences a constant deceleration of 0.5 m/s², it would take approximately 40.24 seconds for the car to slow down from a velocity of 20.12 m/s (45 m/h) to a complete stop.