# Physics [NSTSE (National Science Talent Search Exam- Unified Council) Class 9]: Questions 279 - 284 of 285

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## Question 279

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### Question

MCQ▾

A bullet of mass moving with a speed strikes a rest wooden block of mass and gets embedded in it. If the speed of the embedded block is , then ratio of the speeds is:

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 280

Physics
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### Question

MCQ▾

A person standing near the cliff shouted and heard the echo after . If the speed of the sound in air is , how far the person standing from the cliff?

### Choices

Choice (4)Response

a.

b.

c.

d.

All of the above

## Question 281

Physics
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### Question

MCQ▾

A particle is moving with the speed more than the speed of sound. That means it is called particle is moving with:

### Choices

Choice (4)Response

a.

Supersonic speed

b.

Infrasonic speed

c.

Sonic speed

d.

Ultrasonic speed

## Question 282

Edit

### Question

MCQ▾

A force acts on a body of mass . The speed of the body changes from to in . Assuming the force to be constant, it magnitude is:

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 283

Physics
Edit

### Question

MCQ▾

Find the time period of a wave whose frequency is ?

### Choices

Choice (4)Response

a.

b.

c.

d.

## Question 284

Physics
Edit

### Question

MCQ▾

The acceleration due to gravity on the surface of moon is of the value on earth. The time period of a simple pendulum of length at the surface of the moon will be:

### Choices

Choice (4)Response

a.

b.

c.

d.