JEE Main Physics: Kinematics Set 2 Exam Quiz!

1. The figure shows the four paths of a ball hit by a batsman in the game of cricket. If there is no air resistance then which of the following is the correct order of the initial horizontal velocity component in decreasing order?

1>4>3>2

2>3>4>1

4>3>2>1

1>2>3>4

The range of any projectile is always proportional to the horizontal component of the initial velocity. In the question projectile, 4 has the longest range so projectile 4 has the highest value of the linear component of the initial velocity.

Explanation

The range of any projectile is always proportional to the horizontal component of the initial velocity. In the question projectile, 4 has the longest range so projectile 4 has the highest value of the linear component of the initial velocity.

2. An object is moving in a circular path of radius 'R' such that its speed 'v' varies as

v space equals beta square root of x

where x is the distance and is a positive constant. What will be the acceleration of the object?

Explanation

3. Which of the following pair of graphs represent the same motion?

1

2

3

4

Only the first pair of graphs represent the same motion as both graphs can be created with the help of other graph. In all other pairs, both the graphs can’t be derived from each other and that’s why they represent different motions.

Explanation

Only the first pair of graphs represent the same motion as both graphs can be created with the help of other graph. In all other pairs, both the graphs can’t be derived from each other and that’s why they represent different motions.

4. The centripetal acceleration of a particle moving in a circle of radius r is given as a_c = n²rt², where n is a positive constant. Which of the following option is correct for the above motion?

Speed of the particle =

Tangential acceleration of the particle =

None of these

Explanation

5. On the basis of the diagram which of the following statement is true:

Particle 1 will reach the ground first

All the particles will reach the ground simultaneously

All the particles will hit the ground with same speed

Only particle 2 and 3 will hit the ground with same speed

Explanation

6. A ball is moving in a circle of a radius of 12 m with a speed of 2 m/s. The speed of the ball increases by 5 m/s in every one second. The total acceleration of the body after one second is:

Explanation

7. Which of the following acceleration vs. time graphs represent the complete motion of an object thrown vertically upward?

Whenever a ball or an object is thrown in the upward direction, the whole motion is completed under gravity. In the first half of the motion, when the object is moving in the upward direction, gravity opposes the motion (Motion is in an upward direction whereas gravity is in a downward direction) that’s why the value of gravity is taken negatively. In the second half of the motion, when the object is moving in the upward direction, gravity supports the motion (Motion is in a downward direction and gravity is also in a downward direction) that’s why the value of gravity is taken positively.

Explanation

Whenever a ball or an object is thrown in the upward direction, the whole motion is completed under gravity. In the first half of the motion, when the object is moving in the upward direction, gravity opposes the motion (Motion is in an upward direction whereas gravity is in a downward direction) that’s why the value of gravity is taken negatively. In the second half of the motion, when the object is moving in the upward direction, gravity supports the motion (Motion is in a downward direction and gravity is also in a downward direction) that’s why the value of gravity is taken positively.

8. A horizontally traveling bullet pierces a paper screen A and then B which are separated by a distance of 45 m. The hole made by the bulletin screen A is 20 cm above the hole in screen B. What will be the velocity of the bullet when it hits screen A? Neglect the resistance of paper and air.

450 m/s

225 m/s

332 m/s

625 m/s

The bullet is traveling horizontally so the vertical component of the velocity will be zero. The complete motion of the bullet will only be due to the horizontal velocity. Let the velocity of the bullet is V0, then the time taken by the bullet in travelling 45 m, T = 45/V₀ Horizontal height travelled by the bullet Y = 0 + $1 half$ gT²; 0.2 = $1 half$ 10T² so T = 0.2s

Velocity of the bullet V₀ = 45/0.2 = 225 m/s

Explanation

The bullet is traveling horizontally so the vertical component of the velocity will be zero. The complete motion of the bullet will only be due to the horizontal velocity. Let the velocity of the bullet is V0, then the time taken by the bullet in travelling 45 m, T = 45/V₀ Horizontal height travelled by the bullet Y = 0 + $1 half$ gT²; 0.2 = $1 half$ 10T² so T = 0.2s

Velocity of the bullet V₀ = 45/0.2 = 225 m/s

9. A ball is projected at an angle

alpha

with the velocity of u. What will be the average velocity between the point of projection and the highest point of the projectile?

Explanation

10. A particle is thrown at some angle within the gravitational field of the earth with some initial velocity. Which of the following graph is not true in this context?

Explanation