Answer:
Explanation:
We are asked to find how much heat a sample of copper absorbs when the temperature is increased.
Since we know the mass, temperature increase, and specific heat capacity, we can use the following formula to calculate heat.
The mass of the copper sample is 100 grams, the temperature is changed or increased by 30.0 degrees Celsius, and the specific heat of copper is 0.39 Joules per gram degrees Celsius.
- m= 100 g
- c= 0.39 J/g °C
- ΔT= 30.0 °C
Substitute the values into the formula.
Multiply the first two values. Note that the units of grams cancel.
Multiply again, this time the units of degrees Celsius cancel.
The copper sample absorbs <u>1170 Joules</u> of heat and <u>Choice B </u>is correct.
Answer: A) grinding coffee beans
Explanation:
A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.
A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.
1. Grinding coffee : Only change in size takes place, thus a physical change
2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.
3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change
4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.
Answer:
Kinetic
Explanation:
Kinetic energy kicks in after potienal builds up energy
Answer:
N2
Explanation:
Rate of effusion is defined by Graham's Law:
(Rate 1/Rate 2) = (sqrt (M2)/ sqrt (M1))
(Where M is the molar mass of each substance. )
Molar Mass of oxygen, O2, is 32 (M1).
Rate of effusion of O2 to an unknown gas is .935(Rate 1).
Rate 2 is unknown so put 1.
Solve for x (M2).
.935/1 = sqrt x/ sqrt32
.935 x sqrt 32 = sqrt x
5.29 = sq rt x
5.29^2 = 27.975 = 28
N2 has a molar mass of 28 so it is the correct gas.
KE = 0
<h3>Further explanation </h3>
Energy is the ability to do work
Energy because its motion is expressed as Kinetic energy (KE) which can be formulated as:
So for two objects that have the same speed, the greater the mass of the object, the greater the kinetic energy
The stone in hand is in a motionless state (at rest) so that its velocity (v) = 0, so it has no kinetic energy
But this stone can have <em>potential energy that is gained due to its height</em>
