The relationship between force and position is shown in the figure given (in one dimensional case). Find the work done by the force in displaying a body from x= 1 cm to x= 5cm is [This question includes concepts from Work, Energy and Power chapter]
1. 10 erg
2. 20 erg
3. 30 erg
4. 40 erg
The kinetic energy k of a particle moving along a circle of radius R depends on the distance covered s as k = as2 where a is a constant. The force acting on the particle is
(1)
(2)
(3) 2 as
(4)
The driver of a car travelling at velocity v suddenly sees a broad wall in front of him at a distance d. He should
(1) Brake sharply
(2) Turn sharply
(3) (1) and (2) both
(4) None of the above
Work done by a frictional force is
(1) Negative
(2) Positive
(3) Zero
(4) All of the above
A block of mass 50 kg slides over a horizontal distance of 1 m. If the coefficient of friction between their surfaces is 0.2, then work done against friction is
(1) 98 J
(2) 72J
(3) 56 J
(4) 34 J
A body of mass m is moving in a circle of radius r with a constant speed v. The force on the body is and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle
(1)
(2) Zero
(3)
(4)
A man pushes a wall and fails to displace it. He does:
1. negative work
2. positive but not maximum work
3. no work at all
4. maximum work
A body moves a distance of 10 m along a straight line under the action of a force of 5 N. If the work done is 25 joules, the angle which the force makes with the direction of motion of the body is
(1) 0°
(2) 30°
(3) 60°
(4) 90°
A particle moves from position to position under the action of force The work done will be
(1) 100 J
(2) 50 J
(3) 200 J
(4) 75 J
Two bodies of masses 1 kg and 5 kg are dropped gently from the top of a tower. At a point 20 cm from the ground, both the bodies will have the same
(1) Momentum
(2) Kinetic energy
(3) Velocity
(4) Total energy