Advertisements
Advertisements
प्रश्न
A man moves on a straight horizontal road with a block of mass 2 kg in his hand. If he covers a distance of 40 m with an acceleration of 0⋅5 m/s2, find the work done by the man on the block during the motion.
Advertisements
उत्तर
Given:
\[\text{ Distance coverd by the man, s = 40 m } \]
\[\text{Acceleration of the man, a = 0 . 5 m} / s^2\]
\[\text{ F = ma } \]
\[ = 2 \times \left( 0 . 5 \right)\]
\[ = 1 N\]
\[\text{ Work done by the man on the block, } W = F \cdot S\]
\[ = 1 \times 40\]
\[ = 40 J\]
APPEARS IN
संबंधित प्रश्न
List all the forces acting on (a) the pulley A, (b) the boy and (c) the block C in figure.

When Neils Bohr shook hand with Werner Heisenberg, what kind of force they exerted ?
A satellite is projected vertically upwards from an earth station. At what height above the earth's surface will the force on the satellite due to the earth be reduced to half its value at the earth station? (Radius of the earth is 6400 km.)
The force with which the earth attracts an object is called the weight of the object. Calculate the weight of the moon from the following data : The universal constant of gravitation G = 6.67 × 11−11 N−m2/kg2, mass of the moon = 7.36 × 1022 kg, mass of the earth = 6 × 1024 kg and the distance between the earth and the moon = 3.8 × 105 km.
A particle is acted upon by a force of constant magnitude which is always perpendicular to the velocity of the plane. The motion of the particle takes place in a plane. It follows that
(a) its velocity is constant
(b) its acceleration is constant
(c) its kinetic energy is constant
(d) it moves in a circular path.
A block of mass 5.0 kg slides down an incline of inclination 30° and length 10 m. Find the work done by the force of gravity.
Find the average force needed to accelerate a car weighing 500 kg from rest to 72 km/h through a distance of 25 m.
A particle of mass m moves on a straight line with its velocity varying with the distance travelled, according to the equation \[\nu = a\sqrt{x}\] , where a is a constant. Find the total work done by all the forces during a displacement from \[x = 0 \text{ to } x - d\] .
A block of mass 2 kg kept at rest on an inclined plane of inclination 37° is pulled up the plane by applying a constant force of 20 N parallel to the incline. The force acts for one second. Find the kinetic energy of the block at the instant the force ceases to act. Take g = 10 m/s2.
A 250 g block slides on a rough horizontal table. Find the work done by the frictional force in bringing the block to rest if it is initially moving at a speed of 40 cm/s. If the friction coefficient between the table and the block is 0⋅1, how far does the block move before coming to rest?
Water falling from a 50-m high fall is to be used for generating electric energy. If \[1 \cdot 8 \times {10}^5 \text{ kg } \] of water falls per hour and half the gravitational potential energy can be converted into electrical energy, how many 100 W lamps can be lit with the generated energy?
In a children's park, there is a slide which has a total length of 10 m and a height of 8⋅0 m . A vertical ladder is provided to reach the top. A boy weighing 200 N climbs up the ladder to the top of the slide and slides down to the ground. The average friction offered by the slide is three tenth of his weight. Find (a) the work done by the ladder on the boy as he goes up; (b) the work done by the slide on the boy as he comes down. Neglect any work done by forces inside the body of the boy

A uniform chain of length L and mass M overhangs a horizontal table with its two third part on the table. The friction coefficient between the table and the chain is μ . Find the work done by friction during the period the chain slips off the table.
A graph of potential energy V(x) verses x is shown in figure. A particle of energy E0 is executing motion in it. Draw graph of velocity and kinetic energy versus x for one complete cycle AFA.

A cylinder of area 300 cm2 and length 10 cm made of material of specific gravity 0.8 is floated in water with its axis vertical. It is then pushed downward, so as to be just immersed. The work done by the agent who pushes the cylinder into the water is ______ J.
Force acting on a particle is (2`hat"i"` + 3 `hat"j"`) N. Work done by this force is zero, when a particle is moved on the line 3y + kx = 5. Here value of k is ______.
If a force varies linearly with displacement, the area under the F-s graph forms:
When force varies non-linearly with displacement, what method must be used to find work?
A particle of mass 'm' and charge 'q' is placed at rest in uniform electric field E and then released. The momentum gained by the particle after moving a distance 'y' is \[\sqrt{2x}.\] Then x is equal to ______.
A particle moves under the effect of a force F = Cx from x = 0 to x = x1. The work done in the process is ______.
