Part 2-Motion in a plane medium

Welcome to your Part 2-Motion in a plane medium

A ball is thrown from a roof top at an angle of 45° above the horizontal. It hits the grount a few seconds later. The ball has the smallest speed during its motion when

It is at the highest point

It is at the point of projection

It hits the ground

Both (b) and (c)

A body executing uniform circular motion has at any instant its velocity vector and acceleration vector

Along the same direction

In opposite direction

Normal to each other

Not related to each other

A stone tied to the end of a string 100 cm long is whirled in a horizontal circle with a constant speed. If the stone makes 14 revolutions in 22 s, then the acceleration of the stone is

16ms¯² (16m/s²)

4ms¯² (4m/s²)

12ms¯² (12m/s²)

8ms¯² (8m/s²)

For a particle performing uniform circular motion, choose the incorrect statement from the following.

Magnitude of particle velocity (speed) remains constant

Particle velocity remains directed perpendicular to radius vector

Direction of acceleration keeps changing as particle moves

Magnitude of acceleration does not remain constant

What is approximately the centripetal acceleration (in units of acceleration due to gravity on earth, g = 10 m s^-2) of an air-craft flying at a speed of through a circular arc of radius 0.6 km?

26.7

16.9

13.5

30.2

An insect trapped in a circular groove of radius 12 cm moves along the groove steadily and completes 7 revolutions in 100 s. The linear speed of the insect is

4.3 cm s¯¹ (4.3 cm/s)

5.3 cm s¯¹ (5.3 cm/s)

6.3 cm s¯¹ (6.3 cm/s)

7.3 cm s¯¹ (7.3 cm/s)

An aircraft is flying at a height of 3400 m above the ground. It the angle subtended at a ground observation point by the aircraft positions 10 s apart is 30° , then the speed of the aircraft is

10.8 ms¯¹ (10.8m/s)

1963 ms¯¹ (1963m/s)

108 ms¯¹ (108m/s)

196.3ms¯¹ (196.3m/s)

A man can swim with a speed of 4 km h¯¹ in still water. He crosses a river 1 km wide that flows steadily at 3 km h¯¹ . If he makes his strokes normal to the river currect, how far down the river does he go when he reaches the other bank?

500 m

600 m

750 m

850 m

The horizontal range of a projectile fired at an angle of 15° is 50 m. If it is fired with the same speed at an angle of 45°, its range will be

60 m

71 m

100 m

141 m

The friction of the air causes vertical retardation equal to one tenth of the acceleration due to gravity (Take g = 10 ms^–2). The time of flight will be decreased by

0%

1%

9%

11%

A boy playing on the roof of a 10m high building throws a ball with a speed of 10 m/s at an angle of 30^o with the horizontal. How far from the throwing point will the ball be at the height of 10 m from the ground (g = 10 m/s², sin 30^o =1/2 , cos30°=√3/2 )

8.66 m

5.20 m

4.33 m

2.60 m

The barrel of a gun and the target are at the same height. As soon as the gun is fired, the target is also released. In which of the following cases, the bullet will not strike the target

Range of projectile is less than the initial distance between the gun and the target

Range of projectile is more than the initial distance between the gun and the target

Range of projectile is equal to the initial distance between the gun and target

Bullet will always strike the target

A body is whirled in a horizontal circle of radius 20 cm. It has angular velocity of 10 rad/s. What is its linear velocity at any point on circular path

10 m/s

2 m/s

20 m/s

√2 m/s

A particle moves along a circle with a uniform speed v. After it has made an angle of 60^o its speed will be

v√2

v/√2

v/√3

v

A particle is moving along a circular path of radius 2 m and with uniform speed of 5 ms^–1. What will be the change in velocity when the particle completes half of the revolution

zero

10 ms¯¹

10√2 ms¯¹

10/√2 ms¯¹

A car is moving with speed 30 m/sec on a circular path of radius 500 m. Its speed is increasing at the rate of 2m/sec². What is the acceleration of the car

2 m/s²

2.7 m/s²

1.8 m/s²

9.8 m/s²

The angular velocity of a particle is given by ω=1.5-3t²+2 , the time when its angular acceleration ceases to be zero will be

25 sec

0.25 sec

12 sec

1.2 sec

A grinding wheel attained a velocity of 20 rad/sec in 5 sec starting from rest. Find the number of revolutions made by the wheel

π/25 rev/sec

1/π rev/sec

25/π rev/sec

None of these

A grind stone starts from rest and has a constant angular acceleration of 4.0 rad/sec². The angular displacement and angular velocity, after 4 sec. will respectively be

32 rad, 16 rad/sec

16 rad, 32 rad/sec

64 rad, 32 rad/sec

32 rad, 64 rad/sec

A bucket tied at the end of a 1.6 m long string is whirled in a vertical circle with constant speed. What should be the minimum speed so that the water from the bucket does not spill, when the bucket is at the highest position (Take g = 10 m/sec²)

4 m/sec

6.25 m/sec

16 m/sec

none

A body slides down a frictionless track which ends in a circular loop of diameter D, then the minimum height h of the body in term of D so that it may just complete the loop, is

h=5D/2

h=5D/4

h=3D/4

h=D/4

A can filled with water is revolved in a vertical circle of radius 4m and the water just does not fall down. The time period of revolution will be

1 sec

10 sec

8 sec

4 sec

A particle in uniformly accelerated motion travels a, b and c distances in xth, yth, and zth second of its motion, respectively. Then a(y - z) + b(z - x) + c (x - y) =

1

0

2

3

A particle moves in a plane with constant acceleration in a direction different from the initial velocity. The path of the particle will be

A straight line

An arc of a circle

A parabola

An ellipse

A ball is thrown upwards and it returns to ground describing a parabolic path :Which of the following remains constant

Kinetic energy of the ball

Speed of the ball

Horizontal component of velocity

Vertical component of velocity

Part 2-Motion in a plane medium

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