Can work be done on a system if there is no motion? No, because of the way work is defined. Does the centripetal force acting on an object do work on the object? No, because the force and the displacement of the object are perpendicular.

Hooke’s law says F(x) = kx where k is a constant for that spring, and F(x) is the force necessary to keep the spring stretched (or compressed) x units beyond (or short of) its natural length. EX 1 A force of 6 lbs is required to keep a spring stretched 1/2 ft beyond its normal length.

How does the work required to stretch a spring 2 cm compare with the work required to stretch it 1 cm? The elastic potential energy is 1/2 kx2. So in the second case, the elastic PE is 4 times greater than in the first case. Thus, the work required to stretch the spring is also 4 times greater.

Kinetic energy can’t be negative, although the change in kinetic energy Δ K /Delta K ΔK can be negative. Because mass can’t be negative and the square of speed gives a non-negative number, kinetic energy can’t be negative.

If the object’s speed increases, then its kinetic energy will increase. If the kinetic energy increases, the change in kinetic energy will be positive. Since the Work/Energy Equation guarantees that the work done equals the change in kinetic energy, the work done must be positive.

When an object is moving with constant velocity, it means that there is 0 acceleration and hence no force and no work done. Generally an object, when it moves with constant velocity, is overcoming some friction and some force is being applied to balance it.

As is implied by the equation for power, a unit of power is equivalent to a unit of work divided by a unit of time. Thus, a Watt is equivalent to a Joule/second. Thus, the power of a machine is the work/time ratio for that particular machine. A car engine is an example of a machine that is given a power rating.

Use the formula for power: Power = Voltage x Current, or P = VI. If you are trying to calculate the minimum load and you happen to only know the power and voltage ratings of your power supply, you can use the formula P = V2/R, which can become R = V2/P.

This theory predicts that the most likely coalition to form in a group will be one that wins but comprises the individuals with the smallest amounts of power consistent with this outcome. …

Power (P) is the rate at which energy is transferred or converted. Thus, power equals work divided by time (P = W / t). The SI unit of power is the watt (W), in honor of Scottish inventor James Watt (1736 – 1819).

The minimum load is usually the highest resistance that draws the least current from the supply. When the minimum load conditions are not met, the power supply may experience some instability such as flickering and shutdowns. The minimum load for resistive load can be calculated if the minimum current is known.

At the most basic level, load resistance is the cumulative resistance of a circuit, as seen by the voltage, current, or power source driving that circuit. A load resistor is a resistor that has the sole function of increasing the load resistance of the circuit to a specific level.

Graph of Power against Load Resistance From the above table and graph we can see that the Maximum Power Transfer occurs in the load when the load resistance, RL is equal in value to the source resistance, RS that is: RS = RL = 25Ω.

Load resistors are used for impedance matching, maximum power transfer, to improve output stability, and to ensure a minimum of current circulation. In switching power supplies, they are essential to ensure the correct PSU operation.

Resistance is the path and the Load will use the path when it’s needed.

The load resistance in a circuit is the effective resistance of all of the circuit elements excluding the emf source. In energy terms, it can be used to determine the energy delivered to the load by electrical transmission and there appearing as internal energy to raise the temperature of the resistor.

Yes, it does get lower. The effect you see is called internal resistance: A practical electrical power source which is a linear electric circuit may <…> be represented as an ideal voltage source in series with an impedance.