Question

A slow jogger runs a mile in 13 min. Calculate speed in. a) in/s b) Km/h

Answer 1

The correct answers are A) 7.4 km/hr and B) 81.2 in/s.

Explanation:
A) The original ratio is 1 mi/13 min. We know that 1 mi = 5280 feet, so we have 5280 ft/13 min.
Each foot is 12 inches, so we have 5280*12 = 63360 in
63360 in/13 min

Each minute is 60 seconds; 13*60 = 780
63360 in/780 sec.

Dividing this, we get 81.2 in/sec.

B) 1 mi/13 min; 1 mile = 1609 m, so we have 1609 m/13 min.
1 m = 1000 km, so 1609 m = 1609/1000 = 1.609 km; this gives us 1.609 km/13 min.
An hour is 60 minutes, so we have 1.609 km/(13/60) hr; dividing this, we get 7.4 km/hr.

Answer 2

Answer:

a) 81.23 in per second  ,  b) 7.44 km / hour.

Step-by-step explanation:

Given: a slow jogger runs a mile in 13 min.

To find: Calculate speed in. a) in/s b) Km/h

Solution : We have given that jogger runs  1 mile = 13 min.

We know that  1 mile = 63360 inches

i minute = 60 second

Then Speed =  $\frac{Distance}{time}$

Then Speed =  $\frac{1 mile}{1 minute}$

a ) In inches / second

Plug   1 mile = 63360 inches

13 mint = 780 second

Speed =  $\frac{63360 inches}{780 second}$

Speed = 81.23 in per second .

b) For km/h

Given 1 mile = 1609 m

1 kilometer =  1000 meter

1 mile = 1.609 km

1 hour = 60 mint

1 mint = 1/60

13 mint = $\frac{13}{60}$.

13 mint= 0.216 hour

Then Speed = Speed =  $\frac{ 1.609 km}{ 0.216 hour}$

Speed = 7.44 km / hour.

Therefore, a) 81.23 in per second  ,  b) 7.44 km / hour.