It is correct! good job :)
The silver coating on the inner bottle prevents heat transfer by radiation, and the vacuum between its double wall prevents heat moving by convection. The thinness of the glass walls stops heat entering or leaving the flask by conduction.
Answer:
Explanation:
The correct answer is option C.
When the battery is operating a remote control toy the energy is converted from potential energy to the kinetic energy.
A battery stores electrical potential from the chemical reaction.
When the circuit is connected to the potential energy of the battery helps in the movement of the toy.
The energy produced by the movement of the control toy is kinetic energy.
Hence, we can say that Potential energy is changed to kinetic energy
Answer:
iv) It is 9x bigger than before
Explanation:
As the amplitudes of the new speakers add directly with the original one, taking into account the phase that they have, the composed amplitude of the sound wave is as follows:
At = A + 4A -2A = 3 A
The intensity of the wave, assuming it propagates evenly in all directions, is constant at a given distance from the source, and can be expressed as follows:
I = P/A
where P= Power of the wave source, A= Area (for a point source, is equal to the surface area of a sphere of radius r, where is r is the distance to the source along a straight line)
For a sinusoidal wave, the power is proportional to the square of the amplitude, so the intensity is proportional to the square of the amplitude also.
If the amplitude changes increasing three times, the change in intensity will be proportional to the square of the change in amplitude, i.e., it will be 9 times bigger.
So, the statement iv) is the right one.
1.3 A
If a clock expends 2 W of power from a 1.5 V battery, what amount of current is supplying
the clock?
solution
as we know
p=vi
i=p/v
=2/1.5
=1.3A
