Sorry for not making questions for the past few months. But now it’s back!. Introduction: Now there will be examples given.
Topic: Speed
Example 1. Betty cycled at an average speed of 15km/hr from her from her house to Archie’s house which was 5km away from her house. How long did she take to reach Archie’s house?
Solution:
D / S = T 5km / 15km/h = 1/3 D = Distance
D / T = S 1/3 = 20min S = Speed
S * T = D T = Time
Ans: 20
Question 1. Mindy takes a ride that travels on an average speed of 8m/s. If the journey is 320m, find the duration of the ride .
Example 2. Sally takes 20 min to walk from home to school. If the distance between her school and home is 2km, find Sally’s average speed in terms of m/min.
Solution:
D / T = S 2km / 20min = 100km
100 m / min
Ans: 100 m/min
The distance between Matt’s house and the playground is 750 m. If he takes 15min to reach the playground from home, find Matt’s average speed in terms of m/min.
Example 3. David travels at an average speed of 3.6km/h.
(a) Find his average speed in terms of m/s.
(b) If he takes 2hr to travel, what is the total distance covered?
Solution:
(a) 1 hr = 3.6 * 1000 = 3600
1min = 3600 / 60 = 60
1 sec = 60 / 60 = 1m/s
(b) 3.6 * 2 = 7.2km
(a) 1m/s
(b) 7.2km
Question 3. A motorist travels at an average speed of 36km/hr
(a) Express his average speed in m/s
(b) Find the distance he travels in 4 hr in terms of km.
(c) Find how far he travels in 15sec in terms of m.
