SureDen
Velocity: Rate of change of position with time is called velocity.
(a) It is a vector quantity
Acceleration Due to Gravity.
The force of attraction exerted by the earth on a body is called gravitational pull or gravity.
The acceler
Formulas and Important Points
1. v = u+ at ... s=ut+(1/2)t2 ..... v2-u2 = 2as .....
Angular Displacement
Rolling on an Inclined Plane
When a body of mass m and radius R rolls down on inclined plane of height ‘h’ a
Displacement y=asinω t
The acceleration of the particle executing S.H.M. at any instant, is defined as the rate of change of its velocity at that instant. So acceleration
An ideal simple pendulum consists of a heavy point mass body suspended by a weightless, inextensible and perfectly flexible string from a rigid support about which it is free
If a particle is accelerated with constant acceleration in an interval of time, then the motion is termed as uniformly accelerated motion in that interval of time.For uniformly accelerated motion along a straight line, following equations can be used
(a) Ist equation of Motion
1. When the velocity is constant, can the average velocity over any time interval differ from the instantaneous velocity at any instant? If so, give an example; if not, explain why.
2. When racing car, in a qualifying two-lap het, covers the first lap with an avera
The force of attraction of earth on bodies, is called force of gravity. Acceleration produced in the body by the force of gravity, is called acceleration due to gravity. It is represented by the symbol g.
In the absence of air resistance, it is found that all bodies (irresp
Apparent Weight of a Body in a Lift.
An object's apparent weight is the upward force (the normal force, or reaction force), typica
If acceleration is variable then you cannot apply equations of motion.
(i) If acceleration is a function of time
a=f(t)
use
Dimensions of a Physical Quantity.
The powers to which fundamental quantities must be raised in order to express the given physical quantity are called its dimensions.
To make it more clear, consider the physical quantity force
Centre of Mass
Centre of mass of a system (body) is a point that moves as though all the mass were concentrated there and all external forces were
Graphs
x-t graphs(Slope of x-t graph gives velocity)
a) for Rest
Position of Object Remains Same
x= constant
v=0
a=0
Newton’s Second Law: The rate of change of linear momentum of a body is directly proportional to the external force applied on the body and this change
For S.H.M. restoring force is proportional to the displacementF∝y o
Oblique Projectile.
In projectile motion, horizontal component of velocity (u cos?), acceleration (g) and mechanical energy remains constant while, speed, velocity, vertical component of velocity (u sin ?), momentum, kinetic energy and potent
Unit of measurements:-
Fundamental units are those which are neither derived from one another nor can be dissolved. Eg. Units of mass, there are 7
Centre of Mass of a Distributed System
A body may be considered to be made up of an indefinitely large number of particles, each
Q1.Why is gravitational potential energy always negative?[1]
Application of Dimensional Analysis.
(1) To find the unit of a physical quantity in a given system of units : In a dimensional formula, replacing M, L and T by the fundamental units of the required system we can get the un
Friction force is of two types.
a) Static&nbs
A point mass suspended from a mass less spring or placed on a frictionless horizontal plane attached with spring (fig.) constitutes a linear harmonic spring pendulum
The motion of an object is called two dimensional, if two of the three co-ordinates are required to specify the position of the object in space changes w.r.t time and
(1) Mass of gas is measured by determining the wt. of empty container and then container filled wet gas and then taking their difference which will give mass of gas.
VECTOR
A physical quantity having magnitude and direction and also obeying the law of vector addition is a vector quantity. A vector quantity is re
Physical Quantity.
A quantity which can be measured and by which various physical phenomenon can be explained and expressed in form of laws of physics is called a physical quantity. For example length, mass, time, force etc.
Test Details
If force, acceleration and time are considered as fundamental quantities, then the dimensions of length will be
Test Details
A student notes time and the constant acceleration of a slowly moving object with a stopwatch. The equation used
is S = (1/2)AT2. The distance S is measured with a meter stick. What is the acceleration with its estimated error?
Test Details
If the buoyant force F acting om an object depends on its volume V immersed in a liquid , the density ρ of the liquid and the acceleration due to gravity g. The correct expression for F can be
Test Details
Terminal velocity acquired by a spherical stone in a liquid depends on cofficient of viscocity ,density of liquid , radius of stone and acceleration due to gravity.They are related as
Test Details
A ball of mass 150g moving with an acceleration 20 m/s2is hit by a force, which acts on it for 0.1 sec. The impulsive force is
Test Details
A man weighs 80Kg He stands on a weighing scale in a lift which is moving upwards with a uniform acceleration of 5m/s2 What would be the reading on the scale. Take g=10 m/s2 &nb
Test Details
An elevator weighing 6000 kg is pulled upward by a cable with an acceleration of 5m/s2. Taking g to be 10m/s2, then the tension in the cable is &nb
Test Details
A monkey of mass 20 kg is holding a vertical rope. The rope will not break when a mass of 25 kg is suspended from it but will break if the mass exceeds 25 kg. What is the maximum acceleration with which the monkey can climb up along the rope (Take g=10m/s2
Test Details
A force of 5 N acts on a body of weight 9.8 N. What is the acceleration produced in m/s2
Test Details
We can also use equations of motion directly if acceleration is variable.
Test Details
When a particle is in motion, its acceleration may be in any direction.
Test Details
When the projectile is at the highest point of its trajectory,the direction of its velocity and acceleration are
Test Details
If an object is moving in a circular motion, then tangential acceleration is non zero
Test Details
A force of 5 N acts on a body of weight 9.8 N. What is the acceleration produced in m/sec1
Test Details
Mass of a person sitting in a lift is 50 kg. If lift is coming down with a constant acceleration of 10 m/sec2. Then the reading of spring balance will be (g = 10m/sec2)
Test Details
At a place where the acceleration due to gravity is 10m sec-1 a force of 5 kg-wt acts on a body of mass 10 kg initially at rest. The velocity of the body after 4 second is
Test Details
A boy whose mass is 50 kg stands on a spring balance inside a lift. The lift starts to ascend with an acceleration of 2ms-2. The reading of the machine or balance (g = 10 ms-2) is
Test Details
Two masses of 5 kg and 10 kg are connected to a pulley as shown. What will be the acceleration of the system (g = acceleration due to gravity)
Test Details
For a particle moving along a straight line, its acceleration must be along the same line.
Test Details
When a particle is in motion, its acceleration may be in any direction.
Test Details
The normal acceleration of the projectile at its highest position is equal to g.
Test Details
Tangential acceleration changes the speed of the particle whereas the normal acceleration changes its direction.
Test Details
When a particle is in motion, its acceleration is always in the direction of motion.
Test Details
A spherical planet far out in space has a mass M0 and diameter D0. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity which is equal to
Test Details
If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earth's surface would
Test Details
The depth at which the effective value of acceleration due to gravity is g/4 is (R = radius of the earth)
Test Details
Acceleration due to gravity on moon is 1/6 of the acceleration due to gravity on earth. If the ratio of densities of earth (ρm) and moon (ρe) is (ρe /ρm) = 5/3 then radius of moon Rm in terms of Re will be
Test Details
The moon's radius is 1/4 that of the earth and its mass is 1/80 times that of the earth. If g represents the acceleration due to gravity on the surface of the earth, that on the surface of the moon is
Test Details
The angular velocity of the earth with which it has to rotate so that acceleration due to gravity on 60° latitude becomes zero is (Radius of earth = 6400 km. At the poles g = 10 ms–2)
Test Details
The moon's radius is 1/4 that of the earth and its mass is 1/80 times that of the earth. If g represents the acceleration due to gravity on the surface of the earth, that on the surface of the moon is
Test Details
The depth at which the effective value of acceleration due to gravity is g/4 is (R = radius of the earth)
Test Details
If the radius of the earth were to shrink by 1% its mass remaining the same, the acceleration due to gravity on the earth's surface would
Test Details
Acceleration due to gravity on moon is 1/6 of the acceleration due to gravity on earth. If the ratio of densities of earth (ρm) and moon (ρe) is (ρe /ρm) = 5/3 then radius of moon Rm in terms of Re will be
Test Details
A spherical planet far out in space has a mass M0 and diameter D0. A particle of mass m falling freely near the surface of this planet will experience an acceleration due to gravity which is equal to
Test Details
The depth d at which the value of acceleration due to gravity becomes 1/n times the value at the surface, is [R = radius of the earth]
Test Details
The acceleration of a body due to the attraction of the earth (radius R) at a distance 2R from the surface of the earth is (g = acceleration due to gravity at the surface of the earth)
Test Details
The height of the point vertically above the earth's surface, at which acceleration due to gravity becomes 1% of its value at the surface is (Radius of the earth = R)
Test Details
Assuming earth to be a sphere of a uniform density, what is the value of gravitational acceleration in a mine 100 km below the earth's surface (Given R = 6400km)
Test Details
A car of mass ‘m’ is driven with acceleration ‘a’ along a straight level road against a constant external resistive force ‘R’. When the velocity of the car is ‘v’, the rate at which the engine of the car is doi
Test Details
A 10 kg mass moves along x-axis. Its acceleration as a function of its position is shown in the figure. What is the total work done on the mass by the force as the mass moves from x=0 to x=8 cm
[AMU (Med.) 2000]
Test Details
A rubber ball is dropped from a height of 5m on a planet where the acceleration due to gravity is not known. On bouncing, it rises to 1.8 m. The ball loses its velocity on bouncing by a factor of &n
Test Details
A car of mass 1250 kg experience a resistance of 750 N when it moves at 30ms–1. If the engine can develop 30kW at this speed, the maximum acceleration that the engine can produce is
Test Details
A car of mass ‘m’ is driven with acceleration ‘a’ along a straight level road against a constant external resistive force ‘R’. When the velocity of the car is ‘v’, the rate at which the engine of the car is doi
Test Details
A car of mass 1250 kg experience a resistance of 750 N when it moves at 30ms–1. If the engine can develop 30kW at this speed, the maximum acceleration that the engine can produce is
Test Details
A 10 kg mass moves along x-axis. Its acceleration as a function of its position is shown in the figure. What is the total work done on the mass by the force as the mass moves from x=0 to x=8 cm
Test Details
If the acceleration due to gravity be taken as the unit of acceleration and the velocity generated in a falling body in one second as the unit of velocity then
Test Details
The displacement of a particle, moving in a straight line, is given by s=2t2+2t+4 where s is in metres
Test Details
The displacement of the particle is given by y=a+bt+ct2−dt4. The i
Test Details
The displacement of the particle is given by y=a+bt+ct2−dt4. The i
Test Details
A body starts from the origin and moves along the x-axis such that velocity at any instant is given by (4t3−2t), where t is in se
Test Details
A body starts from the origin and moves along the x-axis such that velocity at any instant is given by (4t3−2t), where t is in se
Test Details
The speed of a body moving with uniform acceleration is u. This speed is doubled while covering a distance S. When it covers an additional distance S, its speed would become
Test Details
At the top of the trajectory of a projectile, the directions of its velocity and acceleration are
Test Details
A boy standing on a long rail road car throws a ball straight upward. The car is moving on the horizontal road with an acceleration of 1 m/s2 and the projection velocity in the vertical direction is 9.8 m/s. How far behind the boy will the ball fa
Test Details
A solid sphere, a hollow sphere and a ring are released from top of an inclined plane (frictionless) so that they slide down the plane. Then maximum acceleration down the plane is for (no rolling)
Test Details
The acceleration of a body rolling down on an inclined plane does not depend upon
Test Details
The diameters of two planets are in the ratio 4 : 1 and their mean densities in the ratio 1: 2. The acceleration due to gravity on the planets will be in ratio
Test Details
Let g be the acceleration due to gravity at earth's surface and K be the rotational kinetic energy of the earth. Suppose the earth's radius decreases by 2% keeping all other quantities same, then
Test Details
The acceleration due to gravity increases by 0.5% when we go from the equator to the poles. What will be the time period of the pendulum at the equator which beats seconds at the poles
Coming Soon...