2. A phone is being charged using a current of 0.444 A.
If the resistance of the phone is 10 , what is the
voltage being applied to the phone?
Answer:
Explanation:
We're starting a car. We have the fuel in the engine, and when the engine starts, that fuel is converted into power to move the car. The fuel is made of chemicals, right? Propane, gasoline, so on. What kind of energy comes from chemicals? <em>Chemical energy</em>, right?
That fuel is <em>chemical energy</em>, and the energy to move the car must be <em>kinetic/mechanical</em> energy. However, that's not the <em>only</em> source of <em>mechanical energy</em>.
There's another source of <em>mechanical energy</em> here as well: we have an electric battery. What kind of energy is found in a battery? The battery has electricity, and so it has <em>electrical energy</em>. Some of that <em>electrical energy</em> turns into <em>mechanical energy</em> when the car starts up.
But the engine heats up as well, right? There's one more energy that the <em>electrical energy</em> and <em>chemical energy</em> produce here: <em>thermal energy</em>. That's the source of the heat.
I hope this makes sense for you. Have a wonderful day!
Answer:
Explanation:
The motion of the bullet is a uniformly accelerated motion, therefore we can find its acceleration by using the following suvat equation:
where
v is the final velocity
u is the initial velocity
a is the acceleration
s is the distance covered
For the bullet in this problem:
u = 350 m/s is the initial velocity of the bullet
v = 0 is the final velocity (the bullet comes to a stop)
s = 0.125 m is the stopping distance of the bullet
Therefore, by solving the equation for a, we find its acceleration:
And the negative sign tells that the direction of the acceleration is opposite to that of the velocity.
Answer:
0.147 J
Explanation:
The total energy that has been transformed into thermal energy is equal to the loss of gravitational potential energy between the initial situation (bob at h=0.5 m above the ground) and the final situation (bob back but at h=0.45 m above the ground).
Therefore, we have
where
m = 0.3 kg is the mass of the bob
g = 9.8 m/s^2
h1 = 0.5 m is the initial height
h2 = 0.45 m is the final height
Substituting, we find the thermal energy
Therefore, the energy transformed into thermal energy is 0.147 J.
Explanation:
In a chemical reaction, when mass is conserved , the number of atoms or moles of the reactants must be equal to the number of moles or atoms in the products side.
From the diagram, we should carefully look to see if the number of atoms that makes up the reactants are equal to those on the product side.
For example:
A + B → AB
Here, mass is conserved because, on the reactant side, we have 1 atom of A and on the product side we have 1 atom of A
For B, on the reactant side, we have 1 atom of B and on the product side, we have 1 atom of B.
