equal to change in the momentum of a body

equal to rate of change of momentum of a body

JEE Questions for Physics Laws Of Motion Quiz 2

A gun fires N bullets per sec, each of mass m with velocity v. The force exerted by the bullets on the gun is

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0%
2)
0%
0%

The rate of mass of the gas emitted from rear of a rocket is initially 0.1 kgs^-1. If the speed of the gas relative to the rocket is 50 ms^-1 and mass of the rocket is 2 kg, then the acceleration of the rocket (in ms^-2) is

0%
5
0%
5.2
0%
2.5
0%
25

A train is moving with velocity 20 m/s on this dust is falling at the rate of 50 kg/min. The extra force requesed to move this train with a constant velocity will be

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16.66 N
0%
1200 N
0%
1000 N
0%
166.6 N

0%
0°
0%
30°
0%
45°
0%
90°

Consider the following statement.
When jumping from some height, you should bend your knees as you come to rest instead of keeping your legs stiff. Which of the following relations can be useful in explaining the statement? Where following symbols have their usual meaning

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∆p1 = – ∆p2
0%
∆E = – ∆ (PE + KE ) = 0
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F ∆t = m∆v
0%

10000 small balls, each weighing lg, strike one square centimetre of area per second with a velocity 100 ms^-1 in a normal direction and rebound with the same velocity. The value of pressure on the surface will be

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2 × 103 Nm-2
0%
2 × 105 Nm-2
0%
107 Nm-2
0%
2 × 107 Nm-2

A rocket with a lift–off mass 3.5 × 10⁴ kg is blasted upwards with an initial acceleration of 10 ms^-2. Then, the initial thrust of the blast is

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3.5 × 105 N
0%
7.0 × 105 N
0%
14.0 × 105 N
0%
1.75 × 105 N

A shell at rest at the origin explodes into three fragments of masses 1 kg, 2 kg and mkg. The 1 kg and 2 kg pieces fly off with speeds of 5 ms^-1 along x–axis and 6 ms^-1 along y–axis respectively. If the m kg piece flies off with a speed of 6.5 ms^-1 , the total mass of the shell must be

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4 kg
0%
5 kg
0%
3.5 kg
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4.5 kg
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5.5 kg

In the motion of a rocket, physical quantity which is conserved is

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angular momentum
0%
linear momentum
0%
force
0%
work

Diwali rocket is ejecting 50 g of gases per second at a velocity of 400 ms^-1. The accelerating force on the rocket will be

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22 dyne
0%
20 N
0%
20 dyne
0%
100 N

Three guns are aimed at the centre of a circle. They are mounted on the circle, 120° apart. They fire in a timed sequence, such that the three bullets collide at the centre and mash into a stationary lump. Two of the bullets have identical masses of 4.5 g each and speeds of v₁ and v₂. The third bullet has a mass of 2.50 g and a speed of 575 ms^-1. Find the unknown speeds.

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200 ms-1 each
0%
145 ms-1 and 256 ms-1
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536 ms-1 and 320 ms-1
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None of the above

A rifle of 20 kg mass can fire 4 bullets per second. The mass of each bullet is 35 × 10^-3 kg and its final velocity is 400 ms^-1. Then, what force must be applied on the rifle so that it does not move backwards while firing the bullets?

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80 N
0%
28 N
0%
–112 N
0%
–56 N

A shell is fired from a cannon with a velocity v ms^-1 at an angle of θ with the horizontal direction. At the highest point in its path, it explodes into 2 pieces of equal masses. One of the piece retraces its path to the cannon. The speed of the other piece immediately after the explosion is

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0%
vcos θ
0%
2vcos θ
0%
3vcos θ

A rocket of mass 1000 kg is exhaust gases at a rate of 4 kgs^-1 with a velocity 3000 ms^-1. The thrust developed on the rocket is

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12000 N
0%
120 N
0%
800 N
0%
200 N

A force-time graph for a linear motion of a body is shown in the figure. The change in linear momentum between 0 and 7 s is
Physics-Laws of Motion-76477.png

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2 Ns
0%
3 Ns
0%
4 Ns
0%
5 Ns

A man of 50 kg is standing at one end on a boat of length 25m and mass 200 kg. If he starts running and when he reaches the other end, he has a velocity 2 ms^-1with respect to the boat. The final velocity of the boat is (in ms^-1)

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0%
2)
0%
0%

A shell initially at rest explodes into two pieces of equal mass, the two pieces will

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move with different velocities in different directions
0%
move with the same velocity in opposite directions
0%
move with the same velocity in the same direction
0%
be at rest

Impulse is

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a scalar
0%
equal to change in the momentum of a body
0%
equal to rate of change of momentum of a body
0%
a force

A mass of 100 g strikes the wall with speed 5 ms^-1 at an angle as shown in figure and it rebounds with the same speed. If the contact time is 2 x 10^-3 s, what is the force applied?
Physics-Laws of Motion-76485.png

0%
0%
250 N to right
0%
0%
250 N to left

A ball of mass m moves with speed v and it strikes normally with a wall and reflected back normally. If its time of contact with wall is t, then find force exerted by ball on the wall

0%
0%
2)
0%
mvt
0%

The resultant of two forces acting at an angle of 120° is 10 kg–wt and is perpendicular to one of the forces. That force is

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0%
10 kg–wt
0%
0%

A piece of wire is bent in the shape of a parabola y = kx² (y – axis vertical) with a bead of mass m on it. The bead can slide on the wire without friction. It stays at the lowest point of the parabola when the wire is at rest. The wire is now accelerated parallel to the x –axis with a constant acceleration a. The distance of the new equilibrium position of the bead, where the bead can stays at rest with respect to the wire, from the y – axis is

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0%
2)
0%
0%

A steel wire can withstand a load upto 2940 N. A load of 150 kg is suspended from a rigid support. The maximum angle through which the wire can be displaced from the mean position, so that the wire does not break when the load passes through the position of equilibrium, is

0%
30°
0%
60°
0%
80°
0%
85°

If a street light of mass M is suspended from the end of a uniform rod of length L in different possible patterns as shown in figure, then
Physics-Laws of Motion-76503.png

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pattern A is more sturdy
0%
pattern B is more sturdy
0%
pattern C is more sturdy
0%
All will have same sturdiness

The adjacent figure is the part of a horizontally stretched net. Section AB is stretched with a force of 10 N. The tensions in the sections BC and BF are
Physics-Laws of Motion-76505.png

0%
10 N, 11 N
0%
10 N, 6 N
0%
10 N, 10 N
0%
Can't be calculated due to insufficient data

Two particles of equal mass are connected to a rope AB of negligible mass, such that one is at end A and the other dividing the length of the rope in the ratio 1 : 2 from B. The rope is rotated about end B in a horizontal plane. Ratio of the tensions in the smaller part to the other is (ignore effect of gravity)

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4 : 3
0%
1 : 4
0%
1 : 2
0%
1 : 3

A mass M kg is suspended by a weightless string. The horizontal force required to hold the mass at 60° with the vertical is

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Mg
0%
2)
0%
0%

A block of mass 0.18 kg is attached to a spring of force constant 2N/ m . The coefficient of friction between the block and the floor is 0.1. Initially the block is at rest and the spring is unstretched. An impulse is given to the block. The block slides a distance of 0.06 m and comes to rest for the first time the initial velocity of the block in m/s is v= N / 10. Then, N is

0%
2
0%
3
0%
4
0%
6

An object is gently placed on a long converges belt moving with 11 ms^-1.If the coefficient of friction is 0.4, then the block will slide in the belt upto a distance of

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10.21 m
0%
15.125 m
0%
20.3 m
0%
25.6 m

Three blocks of masses m₁ , m₂ and m₃ are connected by massless string as shown kept on a frictionless table.
They are pulled with a force T₃ = 40 N. If m₁ = 10 kg, m₂ = 6 kg and m₃ = 4 kg , the tension T₂ will be
Physics-Laws of Motion-76514.png

0%
20 N
0%
40 N
0%
10 N
0%
32 N

A box of mass 2 kg is placed on the roof of a car. The box would remain stationary until the car attains a maximum acceleration. Coefficient of static friction between the box and the roof of the car is 0.2 and g =10 ms^-2. The maximum acceleration of the car, for the box to remain stationary, is

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8 ms-2
0%
6 ms-2
0%
4 ms-2
0%
2 ms-2

Three blocks of masses 4 kg, 2 kg and 1 kg respectively are in contact on a frictionless table as shown in the figure. If a force of 14 N is applied on the 4 kg block, the contact force between the 4 kg and the 2 kg block will be
Physics-Laws of Motion-76517.png

0%
2 N
0%
6 N
0%
8 N
0%
14 N

Block A of mass 2 kg is placed over block B of mass 8 kg. The combination is placed over a rough horizontal surface. Coefficient of friction between B and the floor is 0.5. Coefficient of friction between A and B is 0.4. A horizontal force of 10 N is applied on block B. The force of friction between A and B is
Physics-Laws of Motion-76519.png

0%
zero
0%
50 N
0%
40 N
0%
100 N

Two masses m₁ =1 kg and m₂ = 2 kg are connected by a light inextensible string and suspended by means of a weightless pulley as shown in the figure. Assuming that both the masses start from rest, the distance travelled by the centre of mass in 2 s is (take, g = 10 m/s²)
Physics-Laws of Motion-76521.png

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0%
2)
0%
0%
0%
4 m

The engine of a car produces an acceleration of 6ms^-2 in the car. If this car pulls another car of the same mass, then the acceleration would be

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6 ms-2
0%
12 ms-2
0%
3 ms-2
0%
1.5 ms-2

Two masses 8 kg and 12 kg are connected at the two ends of a string that goes over a frictionless pulley. Calculate the acceleration of the masses and the tension in the string. (take, g =10 m/s²)

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8 m/s2 , 144 N
0%
4 m/s2 , 112 N
0%
6 m/s2 , 128 N
0%
2 m/s2 , 96 N

The backside of a truck is open and a box of 40 kg is placed 5 m away from the rear end. The coefficient of friction of the box with the surface of the truck is 0.15. The truck starts from rest with 2 m/s² acceleration. Calculate the distance covered by the truck when the box falls off.

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20 m
0%
30 m
0%
40 m
0%
50 m

A block of mass 2 kg is at rest on a floor. The coefficient of static friction between block and the floor is 0.54. A horizontal force of 2.8 N is applied to the block. What should be the frictional force between the block and the floor? (take, g =10 m/S²)

0%
8.8 N
0%
5.8 N
0%
2.8 N
0%
10.8 N

Starting from rest, the time taken by a body sliding down on a rough inclined plane at 45° with the horizontal is twice the time taken to travel on a smooth plane of same inclination and same distance. Then, the coefficient of kinetic friction is

0%
0.25
0%
0.33
0%
0.50
0%
0.75

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0%
2)
0%
0%

A marble block of mass 2 kg lying on ice when given a velocity of 6 ms^-1 is stopped by friction in 10 s. Then, the coefficient of friction is

0%
0.02
0%
0.03
0%
0.06
0%
0.01

A uniform metal chain is placed on a rough table such that one end of it hangs down over the edge of the table. When one–third of its length hangs over the edge, the chain starts sliding. Then, the coefficient of static friction is

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3/4
0%
1/4
0%
2/3
0%
1/3
0%
1/2

Two masses M and M/2 are joined together by means of light inextensible string passed over a frictionless pulley as shown in the figure. When the bigger mass is released, the small one will ascend with an acceleration of
Physics-Laws of Motion-76540.png

0%
0%
2)
0%
0%
g

0%
100 N
0%
110 N
0%
209 N
0%
196 N

The pulleys and strings shown in the figure are smooth and of negligible mass. For the system to remain in equilibrium, the angle θ should be
Physics-Laws of Motion-76547.png

0%
0°
0%
30°
0%
45°
0%
60°

A block B is pushed momentarily along a horizontal surface with an initial velocity v. If μ is the coefficient of sliding friction between B and the surface, block B will come to rest after a time
Physics-Laws of Motion-76549.png

0%
0%
2)
0%
0%

A body is coming with a velocity of 72 kmh^-1 on a rough horizontal surface of coefficient of friction 0.5. If the acceleration due to gravity is 10 ms^-2 , find the minimum distance, it can be stopped.

0%
400 m
0%
40 m
0%
0.40 m
0%
4 m

A block is kept on an inclined plane of inclination θ and length l. The velocity of particle at the bottom of incline is (the coefficient of friction is µ)

0%
0%
2)
0%
0%

In the arrangement shown in figure, the strings are light and inextensible. The surface over which blocks are placed is smooth. What is the acceleration of each block?
Physics-Laws of Motion-76556.png

0%
8 ms-2
0%
4 ms-2
0%
2 ms-2
0%
14 ms-2

A block of mass 2 kg rests on a horizontal surface. If a horizontal force of 5 N is applied on the block, the frictional force on it is ( take, µ_k = 0.4 , µ_s = 0.5 )

0%
5 N
0%
10 N
0%
8 N
0%
zero

JEE Questions for Physics Laws Of Motion Quiz 2 - MCQExams.com

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Practice Physics Quiz Questions and Answers

JEE Questions for Physics Laws Of Motion Quiz 2 - MCQExams.com

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Practice Physics Quiz Questions and Answers

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