A particle moving with velocity is acted by three forces shown by the vector triangle PQR . The velocity of the particle will :

** **

- Option 1)
increase

- Option 2)
derease

- Option 3)
remain constant

- Option 4)
change acording to the smallest force QR

Option 1)
increase
Option 2)
derease
Option 3)
remain constant
Option 4)
change acording to the smallest force QR

Two particle A abd B are moving in uniform circular motion in concentric circles of radii with speed respectively . Their time period of rotation is the same . The ratio of angular speed of A to that of B will be :

- Option 1)
- Option 2)
- Option 3)
- Option 4)
1 : 1

A mass m is attached to a thin wire and whirled in a vertical circle . The wire is most likely to break when :

- Option 1)
The mass is at the highest point

- Option 2)
the wire is horizontal

- Option 3)
The mass is at the lowest point

- Option 4)
Inclined at an angle of 60 degree from vertical

The resultant of weight and centrifugal force is maximum at bottom . so wire is mostly like to break at bottom Option 1)The mass is at the highest point Option 2)the wire is horizontal Option 3)The mass is at the lowest point Option 4)Inclined at an angle of 60 degree from vertical

A block of mass 10 Kg is in contact against the inner wall of a hollow cylinder drum of radius 1 m . The coefficient of friction between the block and the iner wall of the cylinder is 0.1 . The minimum angular velocity needed for the cylinder to keep the block stationary when the cylinder is vertical and rotating about its axis will be

- Option 1)
- Option 2)
- Option 3)
- Option 4)

A body of mass 1 kg begins to move

under the action of a time dependent force

(2ti + 3t^{2}j)N, where i and j are unit

vectors along x and y axis. What power

will be developed by the force at the time

@gulamjilani

P=F.v

v is obtained by integrating acceleration

v=t^2i+t^3j

@ gulamjilani shaikh
The earth rotates from west to east.
If we view from the center of the earth, the trains will be performing Circular Motion.
So, speed of the train that moves from west to east will be greater than that of the train moving from east to west;
as, Speed of train moving from west to east=Speed of the train+wR
and,
Speed of train moving from east to west=Speed of the...

Screenshot_2019-03-05-13-17-01.png

a force F=(6i-8j+10k)N produces accelaration of 1m/s^2 in a body. Calculate mass of the body.

jfjg.PNG
A block of mass m is placed on a smooth inclined wedge ABC of inclination B as shown in the figure. The wedge is given an acceleration 'a' towards the right. The relation between theta and a
for the block to reman stationary on the wedge is

IMG-20190228-WA0000.jpg
27. If a force F of 100 N is applied to block of mass
7 kg, then acceleration of 35 kg mass will be
(g = 10 m/s2)

IMG_20190228_105106.jpg since force of static friction is< 100 N, body moves

Screenshot_632.png

Two blocks of masses 50 Kg and 30 Kg connected by a massless string pass over a tight frictionless , pulley and rest on two smooth planes inclined at angles nad reaspectively with horizontal as shown in the figure .If the system is released from rest then find time taken by 30 Kg block to reach the ground

IMG-20190110-WA0001.jpg The pulleys and strings shown in figure are smooth and of negligible mass . for the system to remain in equilibrium , the angle theta should be

@Sudhir Bali
From force diagram shown in figure,
T' =mg
2T'cosθ=2√mg
So solving this we get
cosθ=1/√2
θ=45

A rope of length L and mass M hangs freely from the ceiling. If the time taken by a transverse wave to travel from the bottom to the top of the rope is T, then time to cover first half length is

T =
so for leth L/2
time period will be T/.

1548152985805-2009603303.jpg

54.

In the given arrangement all surfaces are smooth. What acceleration should be given to the system, for which the

block m2 doesn't slide down?

@Aditya
m1 and m2 doesn't slide down. means, m1 and m2 are rest with respect to M.
now draw free body daigram for m1 and m2
in case of m1,
T = m1a ........(1)
in case of m2,
T = m2g........(2)
from eqs. (1) and (2),

1547444587624-1279057330.jpg A pulley is atttached to the ceiling of a lift moving upward. Two particles are attached to the two ends of a string passing over the pulley. The masses of the particles are in the ratio 2:1. If the acceleration of the particles is g/2 then acc of lift?

@Gourav
Given acceleration of the particles is g/2=a'
now let acceleration of the lift=a upwards
assume lift at rest and apply psudo force=mass* a to both masses
Let masses as 2m and m
2m>m so 2m will move downward with a'
So 2mg+2ma-T=2ma'=2m(g/2)=mg .....(1)
and similarly for m mass
T-mg-ma=ma'=m(g/2) .....(2)
Solving both we get
a=(g/2)

A block is kept on an inclined plane of inclination theta & length l.The velocity of the particle at the bottom of inclined is

Medical

95 Views |

A block of mass m is placed on a smooth inclined wedge ABC of inclination as shown in the figure. The wedge is given an acceleration 'a' towards the right. The relation between a and for the block to remain stationary on the wedge is

- Option 1)
- Option 2)
- Option 3)
- Option 4)

4) a =gtan

Medical

102 Views |

Which one of the following statements is incorrect ?

- Option 1)
Frictional force opposes the relative motion.

- Option 2)
Limiting value of static friction is directly proportional to normal reaction.

- Option 3)
Rolling friction is smaller than sliding friction.

- Option 4)
Coefficient of sliding friction has

dimensions of length.

As we have learned
Kinetic or Dynamic Friction -
kinetic friction
coefficient of kinetic friction
R = reaction
- wherein
depends on the nature of surface in contact.
Coefficient of sliding friction is dimension lessThis is incorrect
Option 1)
Frictional force opposes the relative motion.
This is incorrect
Option 2)
Limiting value of static friction is directly proportional to...

Medical

294 Views |

Two stones of masses m and 2m are whirled in horizontal circles, the heavier one in radius and the lighter one in radius r. The tangential speed of lighter stone is n times that of the value of heavier stone when they experience same centripetal forces. The value of n is:

- Option 1)
3

- Option 2)
4

- Option 3)
1

- Option 4)
2

As we discussed in concept
Force in non-uniform Circular Motion -
Ft = mat
m = mass
ac= centripetal acceleration
at = tangen tial acceleration
Fc = centripetal force
- wherein
W is not equal to zero by tangential force.
W = 0 by centripetal force
i.e n=2
Option 1)
3
This option is incorrect.
Option 2)
4
This option is incorrect.
Option 3)
1
This option is incorrect.
Option...

Medical

228 Views |

The force 'F' acting on a particle fo mass 'm' is indicated by the force-time graph shown below. The change in momentum of the particle over the time interval from zero to 8 s is:

- Option 1)
24 Ns

- Option 2)
20Ns

- Option 3)
12Ns

- Option 4)
6Ns

As we discussed in concept
Impulse -
- wherein
Change in momentum
Area of - area of rectange + area of rectange
Option 1)
24 Ns
This option is incorrect.
Option 2)
20Ns
This option is incorrect.
Option 3)
12Ns
This option is correct.
Option 4)
6Ns
This option is incorrect.

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