Question

A car travels a distance of 15km in 20min. Find the speed of the car in (1)
Km h-1 (2) ms-1

Answer 1

Answer:

If the car travels 15km in 20 minutes, and 20 minutes are a third of an hour, so the speed per hour is : (15km * 3)/(20min * 3) = 45km/60min, as 60min is an hour so it's equal to 45km/h.

Explanation:

Answer 2

Answer:

(1) 45 km/h (2) 12.5 m/s

(1):

1) Work out time in hours - 20/60 = 1/3 hours

2)Get equation speed = distance / time

3)Substitute in values for distance (in km) and time (in hours):

$\frac{15}{1/3}=45$

(2):

1)Work out time in seconds- 20 x 60 = 1200

2)Work out distance in meters - 15 x 1000 = 15000

3)Substitute into equation:

$\frac{15000}{1200}=12.5 ms^-1$