Measurement of Time and Motion Class 7 Questions and Answers Science Chapter 8
Measurement of Time and Motion Class 7 Questions and Answers Science Chapter 8 1. Calculate the speed of a car that travels 150 metres in 10 seconds. Express your answer in km/h. Solution: Distance = 150 m Time taken = 10 s Speed = D i s t a n c e c o v e r e d T i m e t a k e n = 150 m 10 s Speed in km/hr = 15 × 18 5 = 54 km/h 2. A runner completes 400 metres in 50 seconds. Another runner completes the same distance in 45 seconds. Who has a greater speed and by how much? Solution: Runner 1: Distance = 400 m, Time = 50 s Speed = D i s t a n c e c o v e r e d T i m e t a k e n = 400 m 50 s = 8 m/s Runner 2: Distance = 400 m, Time = 50 s Speed = D i s t a n c e c o v e r e d T i m e t a k e n = 400 m 450 s = 8.89 m/s Difference = 8.89 – 8 = 0.89 m/s Hence, speed of runner 2 is greater by approximately 0.89 m/s. 3. A train travels at a speed of 25 m/s and covers a distance of 360 km. How much time does it take? Solution: Speed = 25 m/s Distan...