Unit 3: Work & Energy Review

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What is work in physics?

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Work is defined as the product of the force applied to an object and the distance over which that force is applied in the direction of the force. It is calculated using the formula: Work (W) = Force (F) × Distance (d) × cos(θ), where θ is the angle between the force and the direction of motion.

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What is the formula for calculating the work done on a spring?

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The work done on a spring is calculated using the formula: W = (1/2) k x², where W is the work done, k is the spring constant, and x is the distance the spring is stretched or compressed from its equilibrium position.

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What is the principle of conservation of energy?

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The principle of conservation of energy states that energy cannot be created or destroyed, only transformed from one form to another. The total energy in a closed system remains constant.

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How do you calculate the net work done on an object?

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Net work done on an object can be calculated by summing all the work done by the forces acting on the object. It can also be determined using the work-energy theorem: Net Work = Change in Kinetic Energy (ΔKE).

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What is kinetic energy?

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Kinetic energy is the energy of an object due to its motion. It is calculated using the formula: KE = (1/2) mv², where m is the mass of the object and v is its velocity.

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What is potential energy?

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Potential energy is the energy stored in an object due to its position or configuration. For gravitational potential energy, it is calculated using the formula: PE = mgh, where m is mass, g is the acceleration due to gravity, and h is the height above a reference point.

Front

What is the work-energy theorem?

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The work-energy theorem states that the work done on an object is equal to the change in its kinetic energy. Mathematically, it is expressed as: W = ΔKE = KE_final - KE_initial.

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How do you calculate the work done against friction?

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The work done against friction can be calculated using the formula: Work = Friction Force (F_f) × Distance (d). This work is often negative as it opposes the motion.

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What is the significance of the angle in work calculations?

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The angle (θ) in work calculations determines how much of the applied force contributes to the work done. If θ = 0°, all the force contributes to work; if θ = 90°, no work is done.

Front

What is the formula for gravitational potential energy?

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The formula for gravitational potential energy is: PE = mgh, where PE is potential energy, m is mass, g is the acceleration due to gravity (approximately 9.81 m/s²), and h is the height above a reference point.