NCERT Exemplar Class 11

The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times in a minute. The average work done by a human heart while it beats once is 0.5 J. Calculate the power used by heart if it beats 72 times [...]

Calculate the power of a crane in watts, which lifts a mass of 100 kg to a height of 10 m in 20 seconds. Calculate the power of a crane in watts which lifts a mass of 100 kg to a height of 10 m in 20 seconds. November 9, 2020 Category: Chapter 5 - [...]

In an elastic collision of two billiard balls, which of the following quantities remain conserved during the short time of collision of the balls (i.e., when they are in contact). (a) Kinetic energy . (b) Total linear momentum ? Give reason for your answer in each case. In an elastic collision of two billiard balls [...]

Calculate the work done by a car against gravity in moving along a straight horizontal road. the mass of the car is 400 kg and the distance moved is 2 m. Calculate the work done by a car against gravity in moving along a straight horizontal road. the mass of the car is 400 kg [...]

A body is being raised to a height h from the surface of earth. What is the sign of work done by (a)applied force (b)Gravitational force A body is being raised to a height h from the surface of earth. What is the sign of work done by (a)applied force (b)Gravitational force November 9, 2020 [...]

A rough inclined plane is placed on a cart moving with a constant velocity u on horizontal ground. A block of mass M rests on the incline. Is any work done by force of friction between the block and incline? Is there then dissipation of energy? A man of mass m standing at the bottom [...]

Two blocks M1 and M2 having equal mass are free to move on a horizontal frictionless surface. M2 is attached to a massless spring as shown in figure. Initially M2 is at rest and M1 is moving toward M2 with speed v and collides head-on with M2. A man of mass m standing at the [...]

A man of mass m , standing at the bottom of the staircase of height L climbs it and stands at its top . A man of mass m standing at the bottom of the staircase of height L climbs it and stands at its top . November 9, 2020 Category: Chapter 5 - Work, [...]

Which of the diagrams in figure correctly shows the change in kinetic energy of an iron sphere falling freely in a lake having sufficient depth to impact it a terminal velocity? Which of the diagrams in figure correctly shows the change in kinetic energy of an iron sphere falling freely in a lake having sufficient [...]

In a shotput event an athlete throws the shotput of mass 10 kg with an initial speed of 1m/s at 45^∘ from a height 1.5 m above ground. Assuming air resistance to be negligible and acceleration due to gravity to be 10m/s^2, the kinetic energy of the shotput when it just reaches the ground will [...]