Dropping Objects

Q. A flat plate ofarea 0.1 m2 is placed on a flat surfadeand is separated from it by a film of10- m thick whose coefficient of viscosity1.5 N sm-2. The force required to cause theplate to slide on the surface at constant speed of 1 mm s-1 isace

Q. 8.A bicycle increase its velocity from 10 km/h to 15km/h in 6 seconds.Calculate its acceleration

Q.

A motor car moving with a uniform speed of $20m{s}^{-1}$ comes to rest on the application of brakes after travelling a distance of 10 m. Its acceleration is

1. 

2. 

3. 

4. 

Q. A disc like reel on massless thread unrolls itself while falling downward. the accleration is?

Q.

A body falls freely from rest. It covers as much distance in the last second of its motion as covered in the first three seconds. The body has fallen for a time;

1. 3s

2. 5s

3. 7s

4. 9s

Q. 62. If a particle is accelerated for a time t1 with acceleration a1 and for time t2 with acceleration a2. Then average acceleration is??

Q. Two balls of different masses $m_a$ and $m_b$ are dropped from two different heights $a$ and $b$. The ratio of time taken by the two to drop through these distances is

1. $a:b$
2. $b:a$
3. $\sqrt{a}:\sqrt{b}$
4. $a^2:b^2$

Q. 99. A particle moving with uniform speed v , changes its direction by angle theta in time t. Magnitude of its average acceleration during this time is

Q. vol of 100 gm ball is 500 cm3. find mass of water displace

Q.

Is the statement, “The time taken by a body to reach the highest point is equal to the time taken by the body to fall from the same height” true?

Q. 10. A ball is dropped from a height of 80 m on a floor At each collision ball losses half of its speed then the graph between speed v/s time is

Q.

At time t =0, a rock climber accidentally allows a piton (metal spike) to fall freely from a high point on the rock wall to the valley below him. Then, after a short delay, his climbing partner, who is 10 m higher on the wall, throws a piton downward. The positions 'y' of the pitons versus 't' during the falling are given in figure. With what speed is the second piton was thrown?

1. 17.5 m/s

2. 0 m/s

3. 7.5 m/s

4. 27.5 m/s

Q. When air resistance is taken into account while dealing with the motion of the projectile which of the following properties shows an increase? a. range b. maximum height c. speed with which it strikes the ground d. the angle at which the projectile hits the ground

Q.

A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the first is dropped. The stones strike the water at the same time.

Which of these is the correct velocity time graph of both the stones?

1. 

2. 

3. 

4. 

Q. Water drops fall at regular intervals from a tap which is above the ground. The third drop is leaving the tap at the instant the first drop touches the ground. How far above the ground is the second drop at that instant

1. 2.50 m
2. 3.75 m
3. 4.00 m
4. 1.25 m

Q. If a ball is projected vertical upward from ground such that total distance traveled is 3.6 times of distance travel by the ball in 1st second, then find time of flight of ball ?

Q. Two bodies of different masses $m_a$ and $m_b$ are dropped from two different heights, $a$ and $b$ respectively. The ratio of times taken by the two to drop through these distances is:

1. $a:b$
2. $m_a:m_b$
3. $\sqrt{a}:\sqrt{b}$
4. $a^2:b^2$

Q. at what depth below the earths surface the acceleration due to gravity is decreased by 1%?

Q. A ball is released from the top of a tower of height $h$. It takes time $T$ to reach the ground. What is the position of the ball from ground after time $\frac{T}{3}$?

1. $\frac{h}{9}m$
2. $\frac{7h}{9}m$
3. $\frac{8h}{9}m$
4. $\frac{17h}{18}m$

Q. Q)If a body starting from the rest travels with a uniform acceleration of 10 ms–2 for first 10 second and with uniform acceleration 5 ms–2 for next 20 seconds, then average acceleration of the body for 30 s is

Q. Two bodies $A$ (of mass 1 kg) and $B$ (of mass 3 kg) are dropped from height of 16 m and 25 m, respectively. The ratio of the time taken by them to reach the ground is

1. $\frac{4}{5}$
2. $\frac{5}{4}$
3. $\frac{12}{5}$
4. $\frac{5}{12}$

Q. Find the percentage decreases in the accleration due to gravity when a body is taken from the surface of earth to a height of 64km from its surface

Q.

A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

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2. 

3. 

4. 

Q.

If I drop a ball from a height of 5 m then how long will it take to reach the ground?

1. 1

2. 2

3. 3

4. 5

Q. A flower pot falls off a window sill and falls past the window below. It takes $0.5s$ to pass through a window that is $2.0\text{m}$ above the ground. Find how high is the window sill from the ground?
(Take $g=10m/s^2$)

1. $2.5\text{m}$
2. $2.25\text{m}$
3. $3.25\text{m}$
4. $4.5\text{m}$

Q. A uniform rod of mass M is held vertically on a rough horizontal surface the rod is released at some instant the normal reaction N of the surface on the rod:(As the rod falls) (1)increases continuously from zero (2)decreases continuously from mg(3)remains constant with value mg

Q.

A ball is dropped from the difference of height 5m. Find the velocity with which it hits the ground.

Q. Suggest a suitable physical situation for each of the following graphs (Fig):

Q. a body is dropped from a height H.the time taken to cover second half of the journey in terms of g and H is

Q. A player throws a ball upwards with an initial speed of 29.4 m s¯¹ (a) What is the direction of acceleration during the upward motion of the ball ? (b) What are the velocity and acceleration of the ball at the highest point of its motion ? (c) Choose the x = 0 m and t = 0 s to be the location and time of the ball at its highest point, vertically downward direction to be the positive direction of x-axis, and give the signs of position, velocity and acceleration of the ball during its upward, and downward motion. (d) To what height does the ball rise and after how long does the ball return to the player’s hands ? (Take g = 9.8 m s¯² and neglect air resistance).