work, power and energy Flashcards
(26 cards)
What is the definition of work in physics?
Work is defined as the product of force and the displacement in the direction of the force.
True or False: Work can be done only when there is displacement.
True
What is the formula for calculating work?
W = F × d × cos(θ), where W is work, F is force, d is displacement, and θ is the angle between the force and displacement.
Fill in the blank: The unit of work in the International System of Units (SI) is ______.
joule
What is kinetic energy?
Kinetic energy is the energy possessed by an object due to its motion.
What is the formula for kinetic energy?
KE = 1/2 mv², where KE is kinetic energy, m is mass, and v is velocity.
True or False: Kinetic energy is always positive.
True
What happens to kinetic energy if the velocity of an object is doubled?
Kinetic energy increases by a factor of four.
What is the definition of power in physics?
Power is the rate at which work is done or energy is transferred over time.
What is the formula for calculating power?
P = W/t, where P is power, W is work, and t is time.
Fill in the blank: The unit of power in the International System of Units (SI) is ______.
watt
True or False: One watt is equal to one joule per second.
True
What is the relationship between work, energy, and power?
Work is the transfer of energy, and power measures how quickly that energy transfer occurs.
What is the principle of conservation of energy?
The principle states that energy cannot be created or destroyed, only transformed from one form to another.
Multiple Choice: Which of the following is NOT a form of energy? A) Kinetic B) Potential C) Work D) Thermal
C) Work
What is potential energy?
Potential energy is the energy stored in an object due to its position or configuration.
What is the formula for gravitational potential energy?
PE = mgh, where PE is potential energy, m is mass, g is the acceleration due to gravity, and h is height.
Fill in the blank: The work-energy theorem states that the work done on an object is equal to the change in its ______.
kinetic energy
True or False: An object at rest has kinetic energy.
False
What is the significance of the angle θ in the work formula?
The angle θ determines the component of the force that acts in the direction of the displacement.
Multiple Choice: Which statement is true? A) Work is a scalar quantity B) Kinetic energy can be negative C) Power is a measure of force D) Work does not depend on displacement
A) Work is a scalar quantity
What is the relationship between work and energy?
Work done on an object results in a change in its energy.
True or False: Power can be calculated as the product of force and velocity.
True
What is the effect of friction on work done?
Friction opposes motion and reduces the amount of work done on an object.
