Question

A jogger runs at an average speed of 5.20 mi/h.

(a) How fast is she running in m/s? (Report your answer to the correct number of significant figures.)

____ m/s

(b) How many kilometers does she run in 37.0 min? (Report your answer to the correct number of significant figures.)

_____ km

(c) If she starts a run at 11:15 a.m., what time is it after she covers 4.46 × 10⁴ ft?

_____ p.m.

Answer 1

a)

1 mi = 1.609 km

speed = 5.20 mi/h

= 5.20*1.609 km /h

= 8.367 km /h

= 8.367 *1000 m / (3600 s)

= 2.32 m/s

Answer: 2.32 m/s

b)

t = 37.0 min

= 37.0*60 s

= 2220 s

speed = 2.32 m/s

distance = speed * time

= 2.32 m/s * 2220 s

= 5150.4 m

= 5.15 km

Answer: 5.15 km

c)

1 ft = 30.48 cm = 0.3048 m

so,

distance = 4.46*10^4 ft

= 4.46*10^4 * 0.3048 m

= 1.36*10^4 m

speed = 2.32 m/s

time taken = distance / speed

= 1.36*10^4 m / 2.32 m/s

= 5860 s

= 98 min

= 1 hr 38 min

So, she will reach at 12:53