Measurement of Time and Motion — Question 14

Given
Total distance = 2 km = 2000 m,
Total time = 200
Step 1: Time taken to cover the first 500 m
Time = \(\frac{\text { Distance }}{\text { Speed }}\) = \(\frac{500}{10}\) = 50 s
Step 2: Time taken to cover the next 500 m
Time = \(\frac{500}{10}\) = 100 s
Step 3: Remaining distance = 2000 – 1000 = 1000 m
Remaining time = 200 – 150 = 50 s
Step 4: Speed required to cover the remaining 1000 m
Speed = \(\frac{1000}{50}\) = 20 m/s
Step 5: Average speed = \(\frac{Total distance}{Total time taken }\) = \(\frac{2000}{200}\) = 10 m/s
Class 7 Measurement of Time and Motion Question Answer (Activities)
Activity 8.1: Let Us Construct (Page 107)
Answer:
Do it yourself.
Activity 8.2: Let us Experiment (Pages 109-110)
Answer:
Do it yourself.
Activity 8.3: Let Us Identify (Page 112)
Look at the wall clock shown in Fig. 8.9 carefully. What is the smallest interval of time you can measure with it?
• One second is the smallest interval of time that we can measure using this clock.
Activity 8.4: Let Us Calculate (Pages 114-115)
Table 8.2: Finding the speed of trains Name of the railway station nearest to your place of stay Delhi.
Name of the train
Name of the next station
Distance till the next station (km)
Time taken till the next station(N
Speed of the train between these two stations (km/h)
Vande Bharat
Ambala Cantt.
214
2h 12 min
97.27
Shatabdi Express
Aligarh
158
1h 30 min
105.33
Tejas Express
Kota
465
2h
232.5
Shan-e-Punjab
Panipat
99
1h 25 min
69.88