First Law of Motion

Q.

Write 10 examples of inertia in our daily life.

Q.

Explain the Inertia of rest through some examples.

Q. A force acts on a $2\text{kg}$ object so that its position is given as a function of time as $x=3t^2+5$. What is the work done by this force in first $5$ seconds ?
$\left[\text{Mains-2019, Jan 9th, Shift 2}\right]$

1. $\text{850 J}$
2. $\text{950 J}$
3. $\text{875 J}$
4. $\text{900 J}$

Q. A mass $m$ moves with a velocity $v$ and collides inelastically with another identical mass. After collision, the $1^{st}$ mass moves with velocity $3v$ in a direction perpendicular to the initial direction of motion. Find the speed of the $2^{nd}$ mass after collision.

1. $v$
2. $\sqrt{3}v$
3. $\frac{v}{\sqrt{3}}$
4. $\frac{2v}{\sqrt{3}}$

Q. If the net external force acting on the system of particles is zero, then which of the following may vary?

1. Momentum of the sytem
2. Acceleration
3. Velocity of centre of mass
4. Position of centre of mass

Q. What is magnetic levitation?

Q.

A particle is dropped under gravity from rest from a height h(g=9.8) and it travels a distance 9h/25 in the last second, the height h is

Q. A huge elevator platform is going up at a speed of $20\text{m/sec}$ and during its upward motion a small ball of mass $50\text{gm}$ falling in downward direction strikes the platform elastically at a speed $5\text{m/sec}$. Find the speed in m/sec with which the ball rebounds.

Q.

A body stats falling from height 'h' and travel distance h/2 during last sec of motion then time of travel ( in sec)

Q.

The inertia of an object tends to cause the object ________.

Q.

Statement I: A cloth covers a table. Some dishes are kept on it. The cloth can be pulled out without dislodging the dishes from the table.

Statement II: For every action, there is an equal and opposite reaction.

1. Statement I is correct, Statement II is correct, Statement II is a correct explanation for Statement I

2. Statement 1 is correct, Statement II is correct, Statement II is incorrect explanation for Statement I

3. Statement I is correct, Statement II is incorrect

4. Statement I is incorrect, Statement II is correct

Q.

Prove Galileo's law of odd numbers

Thank😺You

Q.

State Galileo^, s law of inertia.

Q.

An object will continue moving uniformly until

1. The resultant force on it is zero.

2. The resultant force on it increases continuously.

3. The resultant force is at a right angle to its rotation.

4. The resultant force acting on it beings to decrease.

Q. Two objects of the same mass and with the same initial speed, moving in a horizontal plane, collide and move away together at half their initial speed after the collision. The angle (in degree) between the initial velocities of the objects is

Q.

Explain why
a) a horse cannot pull a cart and run in empty space,
b) passengers are thrown forward from their seats when a speeding bus stops suddenly,
c) it is easier to pull a lawn mower than to push it,
d) a cricketer moves his hands backwards while holding a catch.

Q.

When a fast moving bus is stopped suddenly, the passengers sitting in it tend to fall forwards. This is due to

1. inertia of rest.

2. inertia of motion.

3. inertia of direction.

4. inertia of speed

Q.

In a tug of war each of the two teams apply 1000 Newton force at the ends of the rope, which is found to be in equilibrium, the tension in the rope is-

1)1000N

2)2000N

3)500N

4)0

Q. On a stationary sail-boat, air is blown at the sails from a fan attached to the boat (from inside the boat). If the river is still, the boat will

1. Move in a same direction in which air is blown.
2. Spin around
3. Remain stationary
4. Move in a direction opposite to the which air is blown

Q. A particle moves in the $xy-$plane under the action of a force $F$ such that the components of its linear momentum 𝑝 at any time $t$ are $p_x=2\cos t,p_y=2\sin t$. The angle (in degree) between $F$ and $p$ at time $t$ is

Q.

You are riding in a car. The driver suddenly applies the brakes and you are pushed forward. Who pushed you forward?

1. The normal reaction by the car seat

2. The air pressure from behind

3. The friction from the car seat

4. The inertia of your body

Q. In an experiment to measure the height of a bridge by dropping stone into water underneath if the error in measurement of time is0.1 s at the end of2s then the error in estimation of height of bridge will be

Q.

A coin of mass $20g$ is pushed on a table. The coin starts moving at a speed of $25cm/s$ and stops in $5seconds$. Find the force of friction exerted by the table on the coin.

Q.

What happens if there is no inertia?

Q.

A lorry and a car moving with the same momentum are brought to rest by the application of brake, which provide equal retarding force? Which of them will come to rest in shorter time? Which will come to rest in less distance?

Q.

The height of Mercury column in a simple barometer is h as the tube is inclined with the vertical at an angle a. Find the length L of the mercury column along the length of the tube.

Q. If net force acting on system of particles is zero, choose an incorrect option regarding the motion of the centre of mass of the system.

1. Acceleration of COM will always be zero.
2. Both (a) and (b)
3. Velocity of COM will always be zero.
4. None of these

Q. Which of Newton's Laws explains why satellites need very little fuel to stay in orbit?

1. $1^{st}$ Law
2. $2^{nd}$ Law
3. $3^{rd}$ Law
4. Law of conservation of mass

Q. While walking, why do we press the ground with our feet slightly slanted in the backward direction?

Q. An ice cube has been given a push and slides without friction on a level table. Which is correct?

1. It is in neutral equilibrium
2. It is not in equilibrium
3. It is in unstable equilibrium
4. It is in stable equilibrium