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प्रश्न
The graph given alongside shows how the speed of a car changes with time:
(i) What is the initial speed of the car ?
(ii) What is the maximum speed attained by the car ?
(iii) Which part of the graph shows zero acceleration ?
(iv) Which part of the graph shows varying retardation ?
(v) Find the distance travelled in first 8 hours.
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उत्तर
(i) Initial speed of the car is 10 km/h
(ii) Maximum speed attained by the car is 35km/h
(iii) BC represents zero acceleration.
(iv) CD represents varying retardation.
(v) Distance travelled is given by the area enclosed within the curve. So,
Distance travelled = Area or trapezium + Area of rectangle
So distance travelled,
= (1/2)(8+5)(25) + (8)(10)
= 242.5 km
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संबंधित प्रश्न
What do the following measure in a car ?
(a) Speedometer (b) Odometer
Name the physical quantity which gives us an idea of how slow or fast a body is moving.
Arrange the following speed in increasing order (keeping the least speed first
A scooter moving with a speed of 30 km/h.
A motorcyclist drives from place A to B with a uniform speed of 30 km h-1 and returns from place B to A with a uniform speed of 20 km h-1. Find his average speed.
Give one example of a motion where an object does not change its speed but its direction of motion changes continuously.
Express the following in m s-1.
18 km min-1
A car is moving in a straight line with speed 18 km h-1. It is stopped in 5 s by applying the brakes. Find:
- the speed of car in m s-1
- the retardation and
- the speed of car after 2 s of applying the brakes.
The velocity-time graph of a moving body is given below in Figure
Displacement in each part AB, BC and CD.
Define variable velocity and give one example.
Define speed of a body.
