Question

The picture shows the footprints of a man walking. The pace length P is the distance between the rear of two consecutive footprints.
For men, the formula, n P =140, gives an approximate relationship between n and P where,
n = number of steps per minute, and
P = pace length in metres.
b
Bernard knows his pace length is 0.80 meters. The formula applies to Bernard’s walking. Calculate Bernard’s walking speed in meters per minute and in kilometers per hour. Show your working out.

Answer 1

Bernard’s walking speed is 140 meters per minute

Bernard’s walking speed is 8.4 kilometers per hour

Step-by-step explanation:

The pace length P is the distance between the rear of two consecutive footprints

The formula, n P = 140, gives an approximate relationship between n and P where,

• n = number of steps per minute
• P = pace length in meters
• Bernard knows his pace length is 0.80 meters
• The formula applies to Bernard’s walking

We need to calculate Bernard’s walking speed in meters per minute and in kilometers per hour

∵ n = number of steps per minute

∴ n unit is number / minute

∵ P = pace length in meters

∴ P unit is meter

- That means n P unit is meters/minute

∴ n P represents the speed in meters per second

∵ The formula applies to Bernard’s walking

∵ His pace length is 0.80 meters

∵ n P = 140

∴ n(0.8) = 140

- Divide both sides by 0.8

∴ n = 175

- That means he moves 175 steps per minute

∵ The distance he walks in minute = 175 × 0.8 = 140 meters/minute

∴ His speed is 140 meters per minute

Bernard’s walking speed is 140 meters per minute

∵ 1 km = 1000 m

∵ 1 hour = 60 minutes

- Divide the meters by 1000 and the minute by 60 to change

   from meters per minute to kilometers per hour

∴ His walking speed = $\frac{140}{1000}$ ÷ $\frac{1}{60}$

- Change ÷ to × and reciprocal the fraction after the division sign

∴ His walking speed =  $\frac{140}{1000}$ × $\frac{60}{1}$ = 8.4 km/h

Bernard’s walking speed is 8.4 kilometers per hour

Learn more:

You can learn more about the speed in brainly.com/question/5461619

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