# Kinematics-Motion in a Straight Line (NEET (NTA)-National Eligibility cum Entrance Test (Medical) Physics): Questions 35 - 39 of 47

Get 1 year subscription: Access detailed explanations (illustrated with images and videos) to 2142 questions. Access all new questions we will add tracking exam-pattern and syllabus changes. View Sample Explanation or View Features.

Rs. 550.00 or

## Question number: 35

» Kinematics » Motion in a Straight Line

MCQ▾

### Question

The motion of a body is given by the equation dv (t) /dt = 6.0 - 3v (t), where v (t) is speed in m/s and t in sec.

If body was at rest at t = 0

### Choices

Choice (4) Response

a.

The speed varies with the time as v (t) = 2 (1 – e -5t) m/s

b.

The magnitude of the initial acceleration is 6.0 m/s2

c.

The speed is 0.1 m/s when the acceleration is half the initial value

d.

The terminal speed is 4 m/s

## Question number: 36

» Kinematics » Motion in a Straight Line

MCQ▾

### Question

A particle moves towards east with velocity 5 m/s. After 10 seconds its direction changes towards north with same velocity. The average acceleration of the particle is

### Choices

Choice (4) Response

a.

m/s 2 S-W

b.

m/s 2 N-W

c.

zero

d.

m/s 2 N-E

## Question number: 37

» Kinematics » Motion in a Straight Line

MCQ▾

### Question

A 120 m long train is moving towards west with a speed of 10 m/s. A bird flying towards east with a speed of 5 m/s crosses the train. The time taken by the bird to cross the train will be

### Choices

Choice (4) Response

a.

8 sec

b.

14 sec

c.

16 sec

d.

12 sec

## Question number: 38

» Kinematics » Motion in a Straight Line

MCQ▾

### Question

P, Q and R are three coplanar forces acting at a point and are in equilibrium. Given P = 1.9318 kg wt, sin Q = 0.9659, the value of R is (in kg wt)

### Choices

Choice (4) Response

a.

2

b.

1

c.

0.9659

d.

0.5

## Question number: 39

» Kinematics » Motion in a Straight Line

MCQ▾

### Question

A man can swim with velocity v relative to water. He has to cross a river of width d flowing with a velocity u (w > v). The distance through which he is carried downstream by the river is x. Which of the following statements is correct?

### Choices

Choice (4) Response

a.

If he crosses the river in minimum time x = du/v

b.

x cannot be less than du/v

c.

Force to be minimum he has to swim in a direction making an angle

of π/2- sin -1 (v/u) with the direction of the flow of water.

d.

x will be maximum if he swims in a direction making

an angle of π/2 + sin-1 - 1 (v/u) with direction of the flow of water.

f Page