Recent questions tagged class11

A juggler maintains four balls in motion making each of them raise to a height of 20m from his hand.What time interval should he maintain, for the proper distance between them $(g=10 m/s^2)$

asked Jun 26, 2013 by meena.p

1 answer

In a car race, car A takes less time to finish than car B and passes finishing point with a velocity $v_0$ more than velocity of car B and $t_0$ time earlier than car B. The cars starts from rest and travel with acceleration $a_1$ and $a_2$ respectively. Then ratio of $\large\frac{v_0}{t_0}$ is

asked Jun 26, 2013 by meena.p

1 answer

Two particles start moving from the same point in a straight line. The first moves with constant velocity v and second moves with constant acceleration a. During the time that elapses before the second catches the first, the greatest distance between the particle is

asked Jun 26, 2013 by meena.p

1 answer

A particle is projected vertically from a point A on ground. It takes time $t_1$ to reach point B but still continous to move up. It takes further $t_2$ time to reach the ground from point B. Height of point B from the ground is

asked Jun 26, 2013 by meena.p

1 answer

The velocity time (v-t) graph of a moving object is given by the following figure. The maximum acceleration is

asked Jun 25, 2013 by meena.p

1 answer

A particle is moving in x-y plane with $y=\large\frac{x}{2}$ and $v_x=4-2t$. The displacement versus time of the particle would be

asked Jun 25, 2013 by meena.p

1 answer

A ball is dropped from a certain height on a horizontal floor. The coefficient of restitution between ball and floor is $\large\frac{1}{2}$. The displacement time graph of the ball is

asked Jun 25, 2013 by meena.p

1 answer

A 2m wide truck is moving with a uniform speed of $v_0=8 m/s$ along a staright horizontal road. A pedestrian starts to cross the road with a uniform speed of v when the truck is 4m away from him. The minimum value of 'v' so that he can cross the road safely is

asked Jun 25, 2013 by meena.p

1 answer

Two cars start off to race with velocities 4m/s and 2 m/s and travel in straight line with uniform acceleration $1\; m/s^2$ and $2 m/s^2$ respectively. If they reach the final point at same time, then the length of path is

asked Jun 25, 2013 by meena.p

1 answer

A body travelling along a straight line traversed one third of the total distance with velocity 4 m/s. The remaining part of distance was covered with a velocity $2 m/s$ for half the time and with velocity 6 m/s for other half of time. the mean velocity averaged over whole time of motion.

asked Jun 25, 2013 by meena.p

1 answer

A particle starts from rest at $t=0$ and undergoes an acceleration 'a' in $m/s^2$ with 't' in sec as shown

asked Jun 25, 2013 by meena.p

1 answer

$v_A=(x \hat i+6 \hat j) m/s,v_B=(3 \hat i+2 \hat j) m/s$ find x such that the relative speed of A with respect to B becomes 5 m/s

asked Jun 25, 2013 by meena.p

1 answer

For a motion with constant acceleration which is/are correct?

asked Jun 25, 2013 by meena.p

1 answer

A freely falling body is found to cover $7/16 ^{th} $ of the height of fall during the last second of its motion.Find the height from which it falls $(g=10m/s^2)$

asked Jun 24, 2013 by meena.p

1 answer

A ball is projected horizontaly with a speed v from top of a plane inclined at an angle $45^{\circ}$ with the horizontal. How far from the point of projection will the ball strike the plane

asked Jun 24, 2013 by meena.p

1 answer

A ball is dropped vertically from a height 'd' above the ground. it hits the ground and bounces up vertically to a height $d/2$ neglecting air resistance its velocity 'v' varies with height 'h' above the ground as

asked Jun 24, 2013 by meena.p

1 answer

The time taken by a particle to slide down a smooth inclined plane is double the time it would take in falling down along a height equal to vertical height of the plane. The inclination of the plane with horizontal is

asked Jun 24, 2013 by meena.p

1 answer

A man holds four balls 180 m above the ground and drops them at regular intervals of time so that when the first ball hits ground, fourth ball is just leaving his hand. At this time the second and third balls from the ground are at the positions.

asked Jun 24, 2013 by meena.p

1 answer

A river is flowing with a speed of 1km/hr. A swimmer wants to go to point 'C'. Starting from 'A', he swims with a speed of 5 km/hr at an angle $ \theta$ w.r.t the river. If $AB=BC=400 m$. Then

asked Jun 24, 2013 by meena.p

1 answer

Two fixed frictionless inclined planes making angle $30 ^{\circ}$ and $60 ^{\circ}$ with the vertical are shown. Two blocks A and B are placed on the two planes. What is the relative vertical acceleration of A with respect to B

asked Jun 24, 2013 by meena.p

1 answer

A car travelling with a speed of 60 km/hr can brake to stop within a distance of 20m. If the car is going twice as fast, the stopping distance will be ?

asked Jun 24, 2013 by meena.p

1 answer

Two bodies begin to free fall from same height at a time interval of N seconds, If the vertical seperation between them is 1m after n seconds from the start of 1st body, then n equals

asked Jun 24, 2013 by meena.p

1 answer

A player kicks a football at an angle of $30^{\circ}$ with horizontal and initial velocity of 19.6m/s. A second player standing at a distance of 20.95m from the first player and in the direction of the kick,starts running to meet the ball, at the instant it is kicked. How far and how fast must he run in order to catch the ball before it hits the ground ?

asked Jun 24, 2013 by meena.p

1 answer

The velocity-time graph of a moving body is shown in figure. The ratio of acceleration during interval OB and BC is

asked Jun 24, 2013 by meena.p

1 answer

Rain is falling at the speed of 4 km/hr from west direction making an angle $30^{\circ}$ with vertical. At what speed should a man walk eastward, such that he has to hold his umbrella vertically to protect himself

asked Jun 23, 2013 by meena.p

1 answer

A particle starts from rest from top of an inclined plane of a given base. The time of fall is least when the inclination of the plane to the horizon is

asked Jun 23, 2013 by meena.p

1 answer

The displacement x of a particle varies with time 't' as $x=ae^{-\alpha t}+b e^{\beta t}$ where $a,b,\alpha, \beta$ are positive constants. The velocity of the particle will

asked Jun 23, 2013 by meena.p

1 answer

The position x of a particle varies with time as $x=at^2-bt^3$. The acceleration of the particle will be zero at time t equal to

asked Jun 21, 2013 by meena.p

1 answer

Two boys are standing at ends A and B of a ground where AB=a. The boy at B starts running in a direction perpendicular to AB with a velocity v$_1$. The boy at A starts running simultaneously with velocity v and catches the other boy in a boy in a time t. Calculate t in terms of a, v and v$_1$.

asked Jun 21, 2013 by meena.p

1 answer

A block of mass 10kg is dropped from top of a cliff 100m high at same time a bullet of mass 10g is fired vertically upward with velocity of 100m/s. after how much time will they meet ?

asked Jun 21, 2013 by meena.p

1 answer

A plane is flying horizontally at an attitude of 490 m with a velocity of 80 m/s. A bomb is dropped from it. After how much time does the bomb reach the ground ?

asked Jun 21, 2013 by meena.p

1 answer

A stone is dropped from a $25^{th}$ storey of a multistoreyed building. and it reaches the ground in $5\; sec$. How many storeys does it pass through in the 1st second ? ( g = 9.8m/s )

asked Jun 21, 2013 by meena.p

1 answer

A balloon is rising steadily at 5m/s. when it reaches a height of 30 m, a stone is dropped from it. After how much time will the stone reach the ground ?

asked Jun 21, 2013 by meena.p

1 answer

A ball is thrown upward from a bridge with an initial velocity of 4.9 m/s. It strikes water after 2s. If $g=9.8 m/s^2$ What is the height of the bridge ?

asked Jun 20, 2013 by meena.p

1 answer

A 150 m long train is travelling from West to East at a speed of 20 m/s. A bird is flying from East to West at a speed of 5 m/s above the train. How long will the bird take to cross the train ?

asked Jun 20, 2013 by meena.p

1 answer

A man crosses the river in shortest time at an angle $\theta=60 ^{\circ}$ to the direction of flow of water. If the speed of water is $v_w=4\; km/hr$ find the speed of man.

asked Jun 20, 2013 by meena.p

1 answer

A particle moves along a semicircle of radius 10 m in 5 seconds. The average velocity of the particle in m/s is?

asked Jun 20, 2013 by meena.p

1 answer

The correct statement from the following is

asked Jun 20, 2013 by meena.p

1 answer

At what departure angle should a body be projected so that the maximum vertical height attained by a projectile is equal to the horizontal range ?

asked Jun 20, 2013 by meena.p

1 answer

A ball is thrown vertically upwards from ground and a student gazing out of window sees it moving upward past him at 5 m/s. The window is 10 m above the ground.Find the maximum height of the ball.

asked Jun 20, 2013 by meena.p

1 answer

A body is moving along a straight line with a constant acceleration and has velocities 6m/s and 8 m/s at points A and B of its path. Find the velocity at mid point of AB

asked Jun 20, 2013 by meena.p

1 answer

A body is moving due north at 10 m/s. In 1 second the velocity changes to 10 m/s due east. Find the average acceleration of the body.

asked Jun 20, 2013 by meena.p

1 answer

A body covers half of the journey at 40km/hr and seconds half at 60 km/hr speed. Find the average speed of the whole journey

asked Jun 19, 2013 by meena.p

1 answer

Value of acceleration due to gravity is $ 9.8 m/s^2$. Find its value in $km/hr^2$

asked Jun 19, 2013 by meena.p

1 answer

Resistance of metal is given by $R=\large\frac{V}{I}$. $V$ is potential difference, $I$ is current. In a circuit $V=(8 \pm 0.5)v$ and current is $I=(2 \pm 0.2)A$. what is value of resistance with percentage error?

asked Jun 19, 2013 by meena.p

1 answer

The dimensions of electrical resistance is

asked Jun 19, 2013 by meena.p

1 answer

The laser light beamed towards moon from earth takes $2.56s$ to return after reflection at moon's surface. How much is the radius of lunar orbit around earth?

asked Jun 19, 2013 by meena.p

1 answer

To find the value of $g$ using simple pendulum $T=2.00 sec,\;l=50cm.$ was measured. The maximum possible errors in $g$ is (Error in $T$=0.01 sec,$l$=0.1 cm)

asked Jun 19, 2013 by meena.p

1 answer

Heat generated in a circuit is given by $H=I^2Rt$, $I$ is current $R$ is resistance, $t$ is time. If percentage error in measuring $I$, $R$ and $t$ are $2 \%,1\%$ and $1\%$ respectively. what is the maximum error in measuring heat

asked Jun 19, 2013 by meena.p

1 answer

Find the dimension of physical quantity $X$ in the equation $Force=\large\frac{X}{Density}$

asked Jun 19, 2013 by meena.p

2 answers

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