Question

please tell answer urgently ​

Answer 1

Solution -

Section A

Uniform Speed -

When a body covers equal distances in equal intervals of time , it is said to be moving in uniform speed .

Uniform Acceleration -

When the rate of change of velocity of a body is uniform for equal intervals of time , It is said to be moving with uniform Acceleration.

Retardation -

When the acceleration of a body decreases , at any instance of time , it is said to be in retardation of moving in a retarded motion .

Displacement -

This refers to the shortest length of the path travelled by the body .

Which Is Greater -

60 kmph

=> [ 60 × 5/18 ] m / s

=> 20 m/s .

15 m / s .

Now,

20 m / s > 15 m / s.

So , the first value is greater.

Uniformly Accelerated Motion -

When the body moves with a constant acceleration in equal intervals of time , it is said to be moving in an uniformly accelerated motion .

Non - Uniformly Accelerated Motion -

When the body moves with a non - constant acceleration in equal intervals of time , it is said to be moving in a non - uniformly accelerated motion .

Section B -

1. Average Speed Of the Bus -

=> [ Total Distance Travelled ] / [ Total time taken ]

=> [ 320 km ] / [ 8 hours ]

=> 40 kmph.

2. A car moves 20 km with a speed of 40 kmph .

Time taken to cover that distance -

=> [ 1 / 2 ] hr .

Next 20 km - Speed = 60 kmph

Time taken to cover that distance -

=> [ 1 / 3 ] hr .

Total distance travelled by the car -

=> 20 km + 20 km

=> 40 km .

Average Speed - [ Total Distance Travelled ] / [ Total time taken ]

=> 40 km / [ 5 / 6 ] hr

=> [ 40 × 6 ] / 5 kmph

=> 48 kmph.

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