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
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:
202 m/s
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
Particles P and Q are at r→P = 3i^ + 2j^ and r→Q = 2i^ + j^. Their velocities at these positions are v→P = 2i^ + 3j^ and v→Q = 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
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
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
A missile is fired for maximum range with an initial velocity of 20 m/s, then the maximum height of missile is
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
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
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°
0°
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 dv→dt ≠ 0 but dv→dt = 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 dv→dt = 0 but dv→dt≠0.
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
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