Distance

Q.

A ball is gently dropped from a height of $20m$. If its velocity increases uniformly at the rate of $10m{s}^{-2}$, with what velocity will it strike the ground? After what time will it strike the ground?

Q.

Joseph jogs from one end A to the other end B of a straight 300 m road in 2 minutes 30 seconds and then turns around and jogs 100 m back to point C in another 1 minute. What are Josephs average speeds and velocities in jogging from A to B?

Q.

Consider three charges q1, q2, q3 each equal to q at the vertices of an equilateral triangle of side l. What is the force on a charge Q (with the same sign as q) placed at the centroid of the triangle?

Q.

A train is traveling at a speed of 90 km h^-1. Brakes are applied so as to produce a uniform acceleration of –0.5 ms^-2. Find how far the train will go before it is brought to rest?

Q. Two equally charged, identical metal spheres A and B repel each other with a force F. The spheres are kept fixed with a distance r between them. A third identical, but unchargedsphere C is brought in contact with A and then placed at the mid-point of the line joining A and B. The magnitude of the net electric force on C is(a) F(c) F/2(b) 3F/4(d) F/4

Q. A ball is dropped from a platform at the=0 starting from rest after 6 sec another ball is thrown downwards from the same platform with speed v the two balls meet at time 18 sec what is value of v

Q. A wheel of radius 1 meter rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is

1. 
2. 
3. 
4. 

Q.

A train starts from rest and moves with a constant acceleration of $2.0\mathrm{m}/{\mathrm{s}}^2$ for half a minute. The brakes are then applied and the train comes to rest in one minute. Find (a) the total distance moved by train, (b) the maximum speed attained by the train, and (c) the position(s) of the train at half the maximum speed.

Q.

A baby crawls $8$ feet towards the west and then $8$ feet towards the north. It then moves $14$ feet towards the east. How far and in which direction is the baby from the starting point?

Q.

Derive second equation of motion.

Q. A boat can row with a speed of $10km/hr$ in still water. The river flows steadily at $5km/hr$ and the width of the river is $2km$. If the boat man cross the river with reference to minimum distance of approach then time elapsed in rowing the boat will be

1. $\frac{2\sqrt{3}}{5}hr$
2. $\frac{2}{5\sqrt{3}}hr$
3. $\frac{5\sqrt{2}}{3}hr$
4. $\frac{3\sqrt{2}}{5}hr$

Q.

What are the characteristics of displacement?

Q.

An elevator descends into a mine shaft at the rate of 7 meters per minute if the descent starts 10 meters above the ground level how long will it take to reach 410 meters below the ground level?

Q. Water is filled in a container of uniform area of cross section 'A'. A hole of cross sectional area ${}^{\prime }{a}^{\prime }(a<<A)$ is made in the container at a height of 20 m above the base. Water streams out and hits a small block on the surface at some distance from the container. The block is moved on the surface in such a way that the stream always hits the block. The initial velocity of the block (in m/s) is
$(\text{Given}\frac{a}{A}=\frac{1}{20}.\text{Take}g=10{\text{ms}}^{-2})$.

Q.

A driver takes 0.20 s to apply the brake after he sees a need for it. This is called the reaction time of the driver. If he is driving a car at a speed of 54 km/h and the brakes cause a deceleration of 6 m/$s^2$ find the distance traveled by car after he sees the need to put the brakes on.

Q.

A mosquito net over a 7 ft \times 4 ft bed is 3 ft high. The net has a hole at one corner of the bed through which a mosquito enters the net. It flies and sits at the diagonally opposite upper corner of the net.

(a) Find the magnitude of the displacement of the mosquito.

(b) Taking the hole as the origin, the length. of the bed as the X-axis, its width as the Y-axis, and vertically up as the Z-axis, write the components of the displacement vector.

Q.

Two identical conducting spheres carrying different charges attract each other with a force F when placed in air medium at a distance d apart. The spheres are brought into contact and then taken to their original positions. Now the two spheres repel each other with a force whose magnitude is equal to that of the initial attractive force. The ratio between initial charges on the spheres is

Q.

A man is running with velocity 5km/h towards east and rain is falling vertically down with speed 5km/h. Direction of rain w.r.t man is-

(a) 30 degree with vertical

(b) 60 degree with vertical

(c) 45 degree with vertical

(d) 90 degree with vertical

Q.

In $12minutes$ a car whose speed is $35km{h}^{-1}$, travels a distance of:

1. $7km$

2. $14km$

3. $3.5km$

4. $28km$

Q.

Two cars are travelling in the same direction with a velocity of 60 km per hour. they are separated by a distance of 5 km. a truck moving in opposite direction meets the two cars in a time interval of 3 minute. the velocity of the truck in kilometre per hour is ?

Q. The position of a particle along $x-$ axis at time $t$ is given by $x=1+t-t^2\text{m}$. The distance travelled by the particle in first $2\text{sec}$ is

1. $1\text{m}$
2. $2.5\text{m}$
3. $3\text{m}$
4. $2\text{m}$

Q. A wheel of radius 1 meter rolls forward half a revolution on a horizontal ground. The magnitude of the displacement of the point of the wheel initially in contact with the ground is

1. 
2. 
3. 
4. 

Q.

Under what condition will the distance and displacement of a moving object have the same magnitude?

Q.

A stone is dropped from the top of a cliff and is found to travel 44.1m in the last second before it reaches the ground. Find the height of the cliff. (Can we use 1:3:5 method if yes then how)

Q.

When will speed and velocity of the body be equal?

Q.

A train $280m$ long is moving at a speed of $60km/hr$. What is the time taken by it to cross a platform $220m$ long?

Q.

A spy report about a suspected car reads as follows. "The car moved 2.00 km towards east, made a perpendicular left turn, ran for 500 m, made a perpendicular right turn, ran for 4.00 km and stopped". Find the displacement of the car.

Q. A particle starts from rest with uniform acceleration a. Its velocity after n seconds is v. The displacement of the particle in the last two seconds is?

Q. A farmer moves along the boundary of a square field of slide 10 m in 40 s. What will be the magnitude of displacement of the farmer at the end of 2 minutes 20 seconds from his initial position?

Q. A person trying to lose weight by burning fat lifts a mass of $10kg$ upto a height of $1m$, $1000$ times. Assume that the potential energy lost each time he lowers the mass is dissipated. How much fat will he use up considering the work is done only when the weight is lifted up? Fat supplies $3.8\times {10}^{7}J$ of energy per $kg$ which is converted to mechanical energy with a $20\%$ efficiency rate. Take $g=9.8m{s}^{-2}$.

1. $2.45\times {10}^{-3}kg$
2. $6.45\times {10}^{-3}kg$
3. $9.89\times {10}^{-3}kg$
4. $12.89\times {10}^{-3}kg$