Advertisements
Advertisements
प्रश्न
In the case of negative work, the angle between the force and displacement is
पर्याय
0°
45°
90°
180°
Advertisements
उत्तर
180°
Explanation:
Work done is negative when a force acts opposite to the direction of displacement, i.e. the angle between the two directions is 180°.
संबंधित प्रश्न
A ball is placed on a compressed spring. What form of energy does the spring possess? On releasing the spring, the ball flies away. Give a reason.
A ball of mass 0.20 kg is thrown vertically upwards with an initial velocity of 20 m s-1. Calculate the maximum potential energy it gains as it goes up.
A metal ball of mass 2 kg is allowed to fall freely from rest from a height of 5 m above the ground. Taking g = 10 m s−2, calculate:
- the potential energy possessed by the ball when it is initially at rest.
- the kinetic energy of the ball just before it hits the ground?
State whether the object possess kinetic energy, potential energy, or both :
A bird running on the ground ____________.
State whether the object possess kinetic energy, potential energy, or both :
A stretched spring lying on the ground ____________.
What kind of energy is possessed by the following?
A stone kept on roof-top _______________
A boy weighing 40 kg makes a high jump of 1.5 m.
What is his kinetic energy at the highest point?
Water stored in a dam possesses ______.
A stone is thrown upwards as shown in the diagram. When it reaches P, which of the following has the greatest value of the stone?
Name the device or machine which convert :
Chemical energy into electrical energy.
Name the device or machine which convert :
Electrical energy into heat energy.
Name the device or machine which convert :
light energy into heat energy.
How much electrical energy in joules does a 100 watt lamp consume : in 1 minute?
The hanging bob of a simple pendulum is displaced to one extreme position B and then released. It swings towards centre position A and then to the other extreme position C. In which position does the bob have :
(i) maximum potential energy?
(ii) maximum kinetic energy?
How much electric energy in kWh is consumed by an electrical appliance of 1000 watts when it is switched on for 60 minutes?
Name the energy transfers which occur when an electric ball rings.
A microphone converts :
A body of mass 10 kg falls from a height of 20 m to 8 m. Calculate:
- the loss in potential energy of the body, and
- the total energy possessed by the body at any instant? (Take g = 10 m s-2)
