A boy shooting a rubber band across the classroom -->
Elastic potential energy transformed into kinetic energy
<span>The initial energy is the energy stored in the muscles of the boy's arm, which is elastic potential energy. This is converted into motion of the rubber, therefore kinetic energy
A child going down a slide on a playground --> </span>Gravitational potential energy transformed into kinetic energy
On top of the slide, all the energy of the child is gravitational potential energy due to its height with respect to the ground (E=mgh). when it moves down the slide, this is converted into kinetic energy, because the child acquires a speed v (E=1/2 mv^2)
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Rubbing your hands together to warm them on a cold day --> </span>Kinetic energy being transformed into thermal energy <span>
When rubbing hands, we are moving them (kinetic energy), and this energy raises the temperature of the hand's surface (thermal energy)
Turning on a battery operated light --> </span>
Chemical potential energy transformed into radiant energy <span>
A battery works by mean of chemical reactions (chemical potential energy), producing light (so, emitting energy by radiation, i.e. radiant energy)
Using a dc electric motor --> </span> Electrical energy transformed into kinetic energy<span>
A dc electric motor works using currents (so, electrical energy), and the energy produced can be used for example to accelerate a car (kinetic energy)
Using a gas power heater to warm a room --> </span>Chemical potential energy transformed into thermal energy
<span>A gas power heater burns gases (so, chemical reaction, i.e. chemical potential energy) to raise the temperature of the room (thermal energy)
Using a hand crank generator to produce electric current --> Kinetic energy transformed into electrical energy
In a hand-crank generator, the handle is being rotated (kinetic energy) in order to produce an electric current (electrical energy)
Using the light in your room that is plugged into the wall --> </span>Electrical energy transformed into radiant energy
<span>The lamp works by using electrical current flowing into a resistor (electrical energy) and it produces light, so it emits energy by electromagnetic radiation (radiant energy)
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Kelvin is a base unit of temperature
scale from SI that defines as zero degree Kelvin (absolute zero). The absolute
zero is a hypothetical statement that all molecular movement stops because
there is no transient of energy for the molecules to move. When converting
temperature in degree Celsius to Kelvin, add 273. You are given 600K and you
are asked to find it in degrees Celsius.
T(K) = T(C) + 273
600 K = T(C) + 273
T(C) = 600 – 273
T(C) = 327 °C
<span>The answer is letter B.</span>
Answer:
τ = 0.00203 seconds
Explanation:
The time constant τ in a R-L circuit is given by
τ = L/R
First we have to find out the equivalent resistance of the circuit.
Since there is a parallel combination of 19 Ω and 6.0 Ω resistor
Req = 19*6/19+6
Req = 4.56 Ω
Now we can find out the time constant
τ = L/R
τ = 0.0093/4.56
τ = 0.00203 seconds
Therefore, the time constant of this circuit is 0.00203 seconds.
