A ball is projected at an angle θ with the horizontal. The angle of elevation of the ball when it is at the highest point is:

  •   tan θ2

  •   sin θ2

  •   cos θ2

  •   2 tan θ

A particle is moving along a curve. Select the correct statement.

  • If its speed is constant, then it has no acceleration.

  • If its speed is increasing, then the acceleration of the particle is along its direction of motion.

  • If its speed is decreasing, then the acceleration of the particle is opposite to its direction of motion.

  • If its speed is constant, its acceleration is perpendicular to its velocity.

A man can row a boat with 8 km/h in still water. He is crossing a river of width 8 km, where the speed of water flow is 4 km/h. What direction should he head the boat to cross the river in the shortest time?

  • 30° with the current

  • 60° with the current

  • 90° with the current

  • 120° with the current

A particle is moving 30° north of east with speed 6 m/s. After 3 s the particle is found to be moving along north at the same speed. The magnitude of average acceleration in this interval of time is

                                   

  • 1 m/s2

  • 6 m/s2

  • Zero

  • 2 m/s2

A particle is thrown with a velocity of 40 m/s. If it passes A and B as shown in the figure at time t1 = 1 s and t2 = 3 s. The value of h is:

                              

  • 15 m

  • 10 m

  • 30 m

  • 20 m

At a certain moment, the angle between the velocity vector v and the acceleration a of a particle is greater than 90°. What can be inferred about its motion at that moment?

  • It moves along a curve and its speed is decreasing.

  • It moves along a straight line and accelerated.

  • It moves along a curve and its speed is increasing.

  • It moves along a straight line and it is decelerated.

To a stationary man, the rain is falling on his back with a velocity v at an angle θ with vertical. To make the rain-velocity perpendicular to the man, he:

  • must move forward with a velocity vsinθ.

  • must move forward with a velocity vtanθ.

  • must move forward with a velocity vcosθ.

  • should move in the backward direction.

A particle is thrown from the ground with a speed of 20 m/s at an angle 60° above the horizontal. Average velocity over its entire journey just before hitting the ground is:

  • 10 m/s

  • 20 m/s

  • Zero

  • 15 m/s

A person can throw a ball up to a maximum horizontal range of 400 m. Maximum height to which he can throw the ball is:

  • 200 m

  • 100 m

  • 150 m

  • 250 m

A particle is moving on a circular path of radius 1 m with a speed of 10 m/s. The magnitude of change in its velocity in the interval it subtends an angle 60° at the center is:

  • 10 m/s

  • 20 m/s

  •  202 m/s

  • Zero

A car is moving along east at 10 m/s and a bus is moving along north at 10 m/s. The velocity of the car with respect to the bus is along:

  • North-East

  • South-East

  • North-West

  • South-West

A particle starts moving from the origin in the XY plane and its velocity after time t is given by v = 4i^ + 2tj^. The trajectory of the particle is correctly shown in figure:

  •    
  •   
  •   
  •   

A body A is projected vertically upwards. Another body B of the same mass is projected at an angle of 60° with the horizontal. If both the bodies attain the same maximum height, the ratio of the initial kinetic energy of body A to that of body B is:

  •   34

  •   32

  •   12

  •   12

Particles P and Q are at rP = 3i^ + 2j^ and rQ = 2i^ + j^. Their velocities at these positions are vP = 2i^ + 3j^ and vQ = 3i^ + cj^ respectively. If they collide after one second, then the value of c is

  • 1

  • 2

  • 3

  • 4

Two projectiles are thrown at different angles but their ranges R are the same. If their times of flight are t1 and t2, then the product of their times of flight t1t2 is proportional to

  •   1R

  •   1R2

  •   R2

  •   R

It is raining at 20 m/s in still air. Now a wind starts blowing with speed 10 m/s in the north direction. If a cyclist starts moving at 10 m/s in the south direction, then the apparent velocity of rain with respect to a cyclist will be

  • 20 m/s

  • 202 m/s

  • 105 m/s

  • 30 m/s

A body of mass 2 kg is projected at a speed of 20 m/s from a pillar of height 40 m at an angle of 30° with the horizontal in an upward direction. The speed with which it will hit the ground is

  • 30 m/s

  • 203 m/s

  • 25 m/s

  • 40 m/s

A particle is thrown with velocity u making an angle θ with the horizontal. It just crosses the top of two poles each of height h after 1 s and 3 s respectively. The time of flight of the particle is:

  • 4 s

  • 2 s

  • 8 s

  • 6 s

A projectile is moving in the XY plane such that the horizontal and vertical directions are along the X-axis and Y-axis respectively. The projectile is fired from the origin at a large height with initial velocity (50i^ + 20j^) m/s. The time after which instantaneous velocity of the projectile becomes perpendicular to its initial velocity is:     (g=10m/s2)

  • 7.5 s

  • 14.5 s

  • 5.5 s

  • 10.5 s

A particle is thrown from the ground with a speed u at an angle θ above the horizontal. The rate of change of velocity of the particle at the highest point of the path is:

  • gsinθ

  • gcosθ

  • g

  • Zero

A missile is fired for maximum range with an initial velocity of 20 m/s, then the maximum height of missile is

  • 20 m

  • 30 m

  • 10 m

  • 40 m

A particle is moving along a circle of radius R with constant speed v0. What is the magnitude of change in velocity when the particle goes from point A to B as shown?

                                 

  •   2v0sinθ2

  •   v0sinθ2

  •   2v0cosθ2

  •   v0cosθ2

An open trolley is moving on a horizontal road with constant velocity v1. A man on the trolley throws a ball vertically upward (with respect to trolley) with velocity v2. Select the correct statement.

  • Time of flight of the ball to a man on the ground and the man on the trolley will be different.

  • Maximum height attained by the ball for both men will be different.

  • Horizontal range of the ball for both men will be different.

  • Horizontal range of the ball for both men will be the same.

Two stones are thrown simultaneously from the top of a building horizontally but in opposite directions, they will be moving perpendicular to each other say after time t, then t is equal to ___________. The initial speeds of stones are u1 and u2 respectively and acceleration due to gravity is g.

  •   u1u2g

  •   u1u2g

  •   u1u2g2

  •   2u1u2g

Two projectiles projected with the same speed at angles θ and (90° - θ) from the same point, then H1 × H2 is equal to: (where symbols have their usual meanings)

  •   R216

  •   R28

  •   R24

  •   R2

A projectile is projected from the ground with speed 20 m/s at an angle 30° with vertical. The radius of curvature of the path of a projectile, when velocity makes 30° with horizontal is (g = 10 m/s2)

  • 8.5 m

  • 15.4 m

  • 26.2 m

  • 32.6 m

A projectile is projected with speed u at an angle of 30° with the vertical from the ground. The angle between the acceleration of the projectile and its velocity at the time of striking the horizontal ground is:

  • 30°

  • 60°

  • 45°

Which of the following statements is incorrect?

  • The average speed of a particle in a given time interval cannot be less than the magnitude of the average velocity.

  • It is possible to have a situation dvdt  0 but dvdt = 0.

  • The average velocity of a particle is zero in a time interval. It is possible that instantaneous velocity is never zero in that interval.

  • It is possible to have a situation in which dvdt = 0 but dvdt0.

A man is walking on a horizontal road with a speed of 4 km/h. Suddenly, the rain starts vertically downwards with a speed of 7 km/h. The magnitude of the relative velocity of the rain with respect to the man is:

  • 33 km/h

  • 65 km/h

  • 8 km/h

  • 4 km/h

A particle of mass 6 kg moves with an initial velocity of v = 8i^ + 8j^ m/s. A constant force of F=-30j^ N is applied to the particle. Initially, the particle was at (0, 0). The x-coordinate of the particle, when its y-coordinate again becomes zero is given by

  • 6.0 m 

  • 12.8 m

  • 8 m

  • 25.6 m

0:0:1


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