A man walks on a straight road from his home to a market 2.5 km away with a speed of 5km/h. Finding the
market closed, he instantly turns and walks back home with a speed of 7.5 km/h. Find the magnitude of
average velocity and average speed of the man over the interval of time :
(a) 0 to 30 minutes
(b) 0 to 50 minutes
(c) 0 to 40 minutes
Answers
Answer:
A man walks on a straight road from his home to a market 2.5 km away with a speed of 5km/hr. finding the market closed he instantly turns and walks back home with a speed of 7.5km/hr. the average speed of the man over the interval of time 0 - 40 min is equal to?? ( i need solution)
a) 5km/hr
b) 25/4km/hr
c) 30/4km/hr
d) 45/8 km/hr
D)45/8 Km /h
Explanation:
#0 to 40 min
Speed of the man = 7.5 km/h
Distance travelled in first 30 min = 2.5 km
Distance travelled by the man (from market to home) in the next 10 min
= 7.5 × 10/60 = 1.25 km
Net displacement = 2.5 – 1.25 = 1.25 km
Total distance travelled = 2.5 + 1.25 = 3.75 km
Average velocity = Displacement / Time = 1.25 / (40/60) = 1.875 km/h
Average speed = Distance / Time = 3.75 / (40/60) = 5.625 km/h
Explanation: