Ann is driving down a street at 52 km/h.
Suddenly a child runs into the street.
If it takes Ann 0.701 s to react and apply
the brakes, how far will she have moved before
she begins to slow down?
Answer in units of m.
To find the distance Ann will have moved before she begins to slow down, we need to calculate the distance she would have traveled in the time it takes her to react and apply the brakes.
Given:
Initial speed (v) = 52 km/h
Time to react and apply brakes (t) = 0.701 s
First, we need to convert the initial speed from km/h to m/s:
1 km/h = 1000 m/3600 s = 5/18 m/s
So, the initial speed (v) in m/s is:
v = 52 km/h * (5/18) m/s = 130/9 m/s
Now, we can calculate the distance (d) traveled during the reaction time using the formula:
d = v * t
d = 130/9 m/s * 0.701 s
Calculating:
d = 0.701 * (130/9)
d ≈ 10.125 m
Therefore, Ann will have moved approximately 10.125 meters before she begins to slow down.
To find the distance Ann will have moved before she begins to slow down, we need to first calculate the distance covered during her reaction time.
Step 1: Convert Ann's speed from km/h to m/s.
Since the formula for distance is defined in meters, we need to convert Ann's speed from kilometers per hour (km/h) to meters per second (m/s).
1 km = 1000 m
1 hour = 3600 s
To convert km/h to m/s, we need to divide by 3.6:
52 km/h = (52 * 1000) m / (1 * 3600) s = 14.44 m/s (rounded to two decimal places).
Now we have Ann's speed in meters per second.
Step 2: Calculate the distance covered during her reaction time.
The distance covered during Ann's reaction time can be found using the formula:
Distance = Speed * Time
Given:
Reaction time (t) = 0.701 s
Speed (v) = 14.44 m/s
Distance = 14.44 m/s * 0.701 s = 10.12 m (rounded to two decimal places).
Therefore, before Ann begins to slow down, she will have moved approximately 10.12 meters.
d = Vo*T.
Vo = 52km/h = 52,000m/3600s. = 14.44 m/s.
d = 14.44 * 0.701 =
d = Vo*T.
Vo = 52km/h = 52,000m/3600s. = 14.44 m/s.
d = 14.44 * 0.701 =