Physics Mock Test- 2 - Class 9 MCQ

Inertia of stone is greater than the inertia of football because mass of stone is higher than the mass of football even both are of same size.

If an object experiences a net zero unbalanced force, then the body moves with a constant velocity, or if it was at rest, then it continues to remain at rest.

Option D is correct.

Mass ad velocity both are considered to be quantities which defines motion.

The combination of both is called quantity of motion. It is momentum.

P = mv

If we consider the situation when force is equivalent to the rate of change of momentum. I.e Force = (change in momentum)(time interval)
 then, change in momentum = Force * (time interval).
Therefore, the unit for momentum can be Newton - second (Ns)

The correct answer is B as
 let the mass=m
then, m-3/4m=m/4
and velocity=2v
kinetic energy=1/2×mv²
=1/2×m/4×(2v²)
=1/2×m/4×4v²
=1/2mv²

The correct answer is B asMomentum = mass × velocity
4 = 25 × v
V = 4/25
V = 6.25

To find the kinetic energy ,
KE = 1/2 m v^2
= 1/2 × 25 ×6.25x6.25
= 78.12 J
 

The correct answer is C as When unbalanced forces act on a body, the body: as it must experience acceleration by the force applied on it.

Torque is the rotational analogue of force and angular velocityis the rotational analogue of linear velocity in rotational mechanics and when no external force act on the body, its velocity is constant. similarly when no torque acts on a body, its angular velocity is constant.

So option D is correct.

here given, mass = 50 kg
Height = 5 m ,   g  = 10 ms^-1
We know,  w = mgh
⇒   w  =  50 * 10 * 5 
⇒    w = 2500 J

When a body is thrown vertically upward its velocity continuously decreases, kinetic energy also decreases and potential energy increases due to increase in height. 

In this case
Displacement = hypotenuse
Displacement = (8² +6²)^1/2 = 10 m

The value of 'g' that is gravity is greater at the poles because the gravitational pull is maximum at the poles and decreases as it comes down toward the equator.

Given The mass of the body on moon is 40 kg , what is the weight on the earth ?

Now we have mass of body on moon m = 40 kg.

We know that weight on earth is given by mass x gravitational force

 So w = m x g

       w = 40 x 9.8 m/s²

      w = 392 N

So weight on the earth is 392 N

1.for state - if we exert high force on ice it slowly start converting into water I.e liquid thus state is change by force. 

2.for position - if we push a box it change its position. thus force also change position. 

3. for shape - if we press a clay it will change its shape so we can conclude that force change shape also. 

Therefore Option D is correct.

Apparent weight is lessened by buoyancy, which occurs when an object is immersed in a fluid (a liquid or a gas). For example, an object immersed in water weighs less, according to a spring balance, than the same object in air. The apparent weight of a floating object is zero.

If the weight of water is greater than the upward buoyant force acting on it, then net force W−U acts downwards. Hence the body displaces downwards, that is, sink.

Sound waves in air comprise of compressions and rarefactions. These compressions and rarefactions vibrate in a direction parallel to the direction of wave propagation, which is the fundamental prperty of a longitudinal wave. Hence, sound waves in air are longitudinal waves.

Changing feeble sound to loud sound amounts to increasing the amplitude of vibration as intensity of sound is directly proportional to the square of the amplitude of the sound wave.

The pressure from sound waves makes the eardrum vibrate. The vibrations are transmitted further into the ear via three bones in the middle ear: the hammer(malleus), the anvil (incus) and the stirrup (stapes).

Both velocity and acceleration are in the downward direction. Thus, they will be considered negative as they are vectors and the upward direction is positive.

For a body moving at uniform speed, the distance time graph is a straight line inclined to the time axis, which may pass through origin or some other point on the y- axis.

As in uniform motion, the distance time graph would be a straight line, because the equal distance is covered in equal units of time. 

The spring balances are hooked and pulled in opposite direction. By the action-reaction pair force, the reading must be equal to 2.0 N. 

Reaction force: Force that the glove exerts on the ball is the reaction force, opposite to the impact of the ball on the player’s glove.

In case if a body is at a rest position the force acting on the body is equal to the weight of the body which is acting downward on the body and this is equal to the product of mass of the body and the acceleration due to gravity.

⇒ F = W = Mg

Where, W = weight of the body, M = mass of the body and g = acceleration due to gravity.

Now as we know that the acceleration due to gravity is not the same it is dependent on the latitude. I.e. it is increasing on increasing the latitude and vice-versa.

Now as we know that the latitude is minimum at the equator and maximum at the poles on the surface of the earth.

So the acceleration due to gravity is minimum at the equator and maximum at the poles on the surface of the earth.

Now the weight of the body is directly proportional to the acceleration due to the gravity on the surface of the earth.

So the weight of the body is maximum at the poles and minimum at the equator on the surface of the earth.

So this is the required answer.

While, mass m is the measure of how much matter is present in the object.

Weight is given by w = mg

where, g = acceleration due to gravity.