Ans. Distance between two stations = 240 km
Time taken to cover this distance = 4 hours
Ans. Number of oscillations = 20
Total time taken to complete 20 oscillations = 32 s
Ans. Time taken = 15 min = 15 x 60 = 900 seconds
Speed = 2 m/s
Distance = Speed x Time
= 2 x 900 = 1800 m = 1800/1000 = 1.8 km
Ans. The pendulum is said to have completed one oscillation when its bob, starting from its mean position B, moves to A, to C and back to B.
Ans. Vehicle A is moving faster. Speed of the vehicle is greater if it covers maximum distance in a given interval of time.
(i) Motion of your hands while running. Oscillatory motion
(ii) Motion of a horse pulling a cart on a straight road. Straight line
(iii) Motion of a child in a merry-go-round. Circular motion
(iv) Motion of a child on a see-saw. Oscillatory motion
(v) Motion of the hammer of an electric bell. Oscillatory motion
(vi) Motion of a train on a straight bridge. Straight line
Ans. Distance covered = 57336-57321 = 15 km
Time taken = 8:50 – 8:30 = 20 min
Now, convert 20 min into hour = 20/60 = 1/3 h
(i) A car moving with a constant speed.
(ii) A car parked on a side road.
Ans. A car moving with a constant speed.
Image from NCERT
A car parked on a side road.
Image from NCERT
Ans. Case 1
Speed = 40km/h
Time taken = 15 min = 15/60 = ¼ hours
Distance = Speed x Time = 40 X ¼ = 10 km
Case 2
Speed = 60km/h
Time taken = 15 min = 15/60 = ¼ hours
Distance = Speed x Time = 60 X ¼ = 15 km
Total Distance = 10 km + 15 km = 25 km