Part 1-Motion in a plane hard

Welcome to your Part 1-Motion in a plane hard

A body of mass 2 kg has an initial velocity of 3 m/s along OE and it is subjected to a force of 4 Newton’s in OF direction perpendicular to OE. The distance of the body from O after 4 seconds will be

12 m

28 m

20 m

48 m

A projectile is fired at 30^o to the horizontal. The vertical component of its velocity is 80 ms^–1. Its time of flight is T. What will be the velocity of the projectile at t = T/2

80 ms^–1

80√3 ms^–1

(80/√3) ms^–1

40 ms^–1

A particle is projected from point O with velocity u in a direction making an angle α with the horizontal. At any instant its position is at point P at right angles to the initial direction of projection. Its velocity at point P is

u tanα

u cotα

u cosecα

u secα

Two seconds after projection a projectile is travelling in a direction inclined at 30^o to the horizontal after one more sec, it is travelling horizontally, the magnitude and direction of its velocity are

2√20 m/sec, 60º

20√3 m/sec, 60º

6√40 m/sec, 30º

40√6 m/sec, 30º

A particle of mass 100 g is fired with a velocity 20 msec^–1 making an angle of 30^o with the horizontal. When it rises to the highest point of its path then the change in its momentum is

√3 kg m sec‾1

1/2 kg m sec‾1

√2 kg m sec‾1

1 kg m sec‾1

A ball is projected upwards from the top of tower with a velocity 50 ms^–1 making angle 30^o with the horizontal. The height of the tower is 70 m. After how many seconds from the instant of throwing will the ball reach the ground

2.33 sec

5.33 sec

6.33 sec

9.33 sec

If for a given angle of projection, the horizontal range is doubled, the time of flight becomes

4 times

2 times

√2 times

1√2 times

A projectile is thrown into space so as to have maximum horizontal range R. Taking the point of projection as origin, the co-ordinates of the point where the speed of the particle is minimum are

(R, R)

(R, R/2)

(R/2, R/4)

(R, R/4)

The speed of a projectile at the highest point becomes 1/√2 times its initial speed. The horizontal range of the projectile will be

u²/g

u²/2g

u²/3g

u²/4g

A projectile thrown with an initial speed u and angle of projection 15^o to the horizontal has a range R. If the same projectile is thrown at an angle of 45^o to the horizontal with speed 2u, its range will be

12 R

3 R

8 R

4 R

The velocity at the maximum height of a projectile is half of its initial velocity of projection u. Its range on the horizontal plane is

√3u²/2g

u²/3g

3u²/2g

3u²/g

A projectile is thrown from a point in a horizontal place such that its horizontal and vertical velocity component are 9.8 m/s and 19.6 m/s respectively. Its horizontal range is

4.9 m

9.8 m

19.6 m

39.2 m

A particle is projected with a velocity v such that its range on the horizontal plane is twice the greatest height attained by it. The range of the projectile is (where g is acceleration due to gravity)

4v²/5g

4g/5v²

v²/g

4v²/√5g

A grasshopper can jump maximum distance 1.6 m. It spends negligible time on the ground. How far can it go in 10 seconds

5√2 m

10√2 m

20√2 m

40√2 m

Pankaj and Sudhir are playing with two different balls of masses m and 2m respectively. If Pankaj throws his ball vertically up and Sudhir at an angle θ, both of them stay in our view for the same period. The height attained by the two balls are in the ratio

2 : 1 (b) 1 : 1 (c) 1 : cosq (d) 1 : secq

1 : 1

1 : cosθ

1 : secθ

A boy aims a gun at a bird from a point, at a horizontal distance of 100 m. If the gun can impart a velocity of 500 ms^–1 to the bullet. At what height above the bird must he aim his gun in order to hit it (take g = 10 ms^–2)

20 cm

10 cm

50 cm

100 cm

The maximum horizontal range of a projectile is 400 m. The maximum height attained by it will be

100 m

200 m

400 m

800 m

Two bodies are projected with the same velocity. If one is projected at an angle of 30^o and the other at an angle of 60^o to the horizontal, the ratio of the maximum heights reached is

3 : 1

1 : 3

1 : 2

2 : 1

A man can throw a stone 80 m. The maximum height to which he can raise the stone is

10 m

15 m

30 m

40 m

A projectile is projected with a kinetic energy K. Its range is R. It will have the minimum kinetic energy, after covering a horizontal distance equal to

0.25 R

0.5 R

0.75 R

R

An aeroplane is flying at a constant horizontal velocity of 600 km/hr at an elevation of 6 km towards a point directly above the target on the earth’s surface. At an appropriate time, the pilot releases a ball so that it strikes the target at the earth. The ball will appear to be falling

On a parabolic path as seen by pilot in the plane

Vertically along a straight path as seen by an observer on the ground near the target

On a parabolic path as seen by an observer on the ground near the target

On a zig-zag path as seen by pilot in the plane

An aeroplane moving horizontally with a speed of 720 km/h drops a food packet, while flying at a height of 396.9 m. The time taken by a food packet to reach the ground and its horizontalrange is (Take g = 9.8 m/sec²)

3 sec and 2000 m

5 sec and 500 m

8 sec and 1500 m

9 sec and 1800 m

A shell is fired from a gun from the bottom of a hill along its slope. The slope of the hill is α = 30^o, and the angle of the barrel to the horizontal β = 60^o. The initial velocity v of the shell is 21 m/sec. Then distance of point from the gun at which shell will fall

10 m

20 m

30 m

40 m

The maximum range of rifle bullet on the horizontal ground is 6 km its maximum range on an inclined of 30⁰ will be

1 km

2 km

4 km

6 km

A body is revolving with a uniform speed v in a circle of radius r. The angular acceleration of the body is

v/r

Zero

v²/r along the radius and towards the centre

v²/r along the radius and away from the centre

Part 1-Motion in a plane hard

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