Physics-
General
Easy
Question
When a man walks on a horizontal surface with constant velocity, work done by
- Friction is zero
- Contact force is zero
- Gravity is zero
- Man is zero
The correct answer is: Man is zero
Since mg & N are perpendicular to velocity 
and 
, work done by these forces is zero. Since no relative sliding occurs during walking, static friction comes into play. Hence the point of application of static frictional force does not move. Therefore no work is done by frictional force.
The man has to lose his body's (internal) energy E, hence performs work because W = DE.
Related Questions to study
Physics-
Figure shows a block P of mass m resting on a horizontal smooth floor at a distance l from a rigid wall. Block is pushed toward right by a distant 
and released. When block passes from its mean position another block of mass m1 is placed on it which sticks to it due to friction so that the combined block just collides with the left wall.
Figure shows a block P of mass m resting on a horizontal smooth floor at a distance l from a rigid wall. Block is pushed toward right by a distant and released. When block passes from its mean position another block of mass m1 is placed on it which sticks to it due to friction so that the combined block just collides with the left wall.
Physics-General
Chemistry-
The number of isomeric pentyl alcohols possible are:
The number of isomeric pentyl alcohols possible are:
Chemistry-General
Chemistry-
Enol content is maximum in:
Enol content is maximum in:
Chemistry-General
Chemistry-
In addition to the standard ring systems (such as cyclohexane), cyclic compounds can also be bicyclic, tricyclic, etc., . or they can be spirocyclic, bicyclic or bridge head carbons. The point of attachment of two rings are caused bridge head atoms .. Some bicyclic compounds· like camphor are commonly found in plants. Others like norbornane can be synthesized in the laboratory. The formal names of bicyclic and related ring systems are based on:
1) Total number of atoms in the molecule.
2) The number of atoms in each bridge connecting the bridge head atoms. These numbers are Written in square bracket in decreasing order. Spirocyclic compounds have two fused rings, but only one bridge head atom. Spirocyclic compounds are named like bicyclic compounds, but have the. prefix spirocyclo.
Which of the following is the correct structure of bicyclo [1.1.0] butane?
In addition to the standard ring systems (such as cyclohexane), cyclic compounds can also be bicyclic, tricyclic, etc., . or they can be spirocyclic, bicyclic or bridge head carbons. The point of attachment of two rings are caused bridge head atoms .. Some bicyclic compounds· like camphor are commonly found in plants. Others like norbornane can be synthesized in the laboratory. The formal names of bicyclic and related ring systems are based on:
1) Total number of atoms in the molecule.
2) The number of atoms in each bridge connecting the bridge head atoms. These numbers are Written in square bracket in decreasing order. Spirocyclic compounds have two fused rings, but only one bridge head atom. Spirocyclic compounds are named like bicyclic compounds, but have the. prefix spirocyclo.
Which of the following is the correct structure of bicyclo [1.1.0] butane?
Chemistry-General
Chemistry-
Select the correct priority for citation as principal group:
Select the correct priority for citation as principal group:
Chemistry-General
Chemistry-
The IUPAC name of the above compound will be:
The IUPAC name of the above compound will be:
Chemistry-General
Chemistry-
(A) The correct IUPAC name for the compound
is I-methyl ethyl cyclopentane.
(R) It is named as derivative of cyc10pentane because the number of carbon atoms in the ring is more than the side chain.
(A) The correct IUPAC name for the compound
is I-methyl ethyl cyclopentane.
(R) It is named as derivative of cyc10pentane because the number of carbon atoms in the ring is more than the side chain.
Chemistry-General
Chemistry-
The compound 
is called:
The compound is called:
Chemistry-General
Chemistry-
The IUPAC name of
is
The IUPAC name of
is
Chemistry-General
Chemistry-
The compound which contains all the four 
and 
carbon atom is:
The compound which contains all the four and carbon atom is:
Chemistry-General
Physics-
The ring shown in the figure is given a constant horizontal acceleration (a0= 
). Maximum deflection of the string from the vertical is 
, then
The ring shown in the figure is given a constant horizontal acceleration (a0= ). Maximum deflection of the string from the vertical is , then
Physics-General
Physics-
A long block A is at rest on a smooth horizontal surface. A small block B, whose mass is half of A, is placed on A at one end and projected along A with some velocity u. The coefficient of friction between the blocks is m
A long block A is at rest on a smooth horizontal surface. A small block B, whose mass is half of A, is placed on A at one end and projected along A with some velocity u. The coefficient of friction between the blocks is m
Physics-General
Physics-
A ball of mass m attached to the lower end of a light vertical spring of force constant k. The upper end of the spring is fixed. The ball is released from rest with the spring at its normal (unstretched) length, and comes to rest again after descending through a distance x
A ball of mass m attached to the lower end of a light vertical spring of force constant k. The upper end of the spring is fixed. The ball is released from rest with the spring at its normal (unstretched) length, and comes to rest again after descending through a distance x
Physics-General
Physics-
A bob of mass m is attached at one end of a string of length l. Other end of the string is fixed point O. Bob is rotating in a circular path of radius l in horizontal plane about O with constant speed v, as shown in the figure. The average force exerted by string on the bob during its
A bob of mass m is attached at one end of a string of length l. Other end of the string is fixed point O. Bob is rotating in a circular path of radius l in horizontal plane about O with constant speed v, as shown in the figure. The average force exerted by string on the bob during its
Physics-General
Physics-
A block of mass m moves towards a light spring of stiffness k on a smooth horizontal plane. If it compresses the spring through a distance x0, the magnitude of total change in momentum of the block is:
A block of mass m moves towards a light spring of stiffness k on a smooth horizontal plane. If it compresses the spring through a distance x0, the magnitude of total change in momentum of the block is:
Physics-General
