Forms & Transfer of Energy (Physics!!)
What is energy?
Energy is defined as the ability to do work. The standard unit for work is the joule, J. The joule is equal to the energy used when applying a force of one Newton over a distance of one metre (1 J = 1 N x m)
What is the kinetic molecular theory?
The kinetic molecular theory states that all matter is composed of particles. The state of a substance is determined by the energy of the particles, the distance between the particles, and the attractive forces between the particles.
What is the general equation of a straight line?
y = mx + b
What is work?
Work is the process of energy transfer to an object when the object is moved by a force.
Explain what the distance between particles is like in a solid, liquid, and gas.
Solids: super close together
Liquid: not as close as solids, but not as far apart as gases
Gas: far away from each other
Given the equation of the line y = -3x + 2, what is the slope of the line?
m = -3
Describe how the potential energy and the kinetic energy of a skier change as the skier progresses from the start of the course to the bottom of the course.
Definitions:
Kinetic energy: Energy that an object posseses due to its motion
At the start of the course (at the top of the hill), the skier has a lot of potential energy but no kinetic energy since it's not moving. As soon as it starts to move, the kinetic energy increases and the potential energy decreases. The kinetic energy is highest and the potential energy is lowest at the bottom of the hill.
Which statement best describes a substance in its solid state?
a) The particles exhibit vibrational, rotational, and translational motions.
b) The particles exhibit vibrational motion only.
c) Particles of the substance interact with one another through numerous collisions.
d) The substance always takes the shape of the container.
e) The substance always fills the container it is in.
b) The particles exhibit vibrational motion only.
A student performed an experiment 3 times to determine the concentration of a substance. She recorded the following values of concentration from the three experiments: 0.54 mol/L, 0.491 mol/L, and 0.51 mol/L.
What is the mean value of concentration?
0.51 mol/L
Which of the following represent(s) a measurement of energy?
a) 14 V
b) 67 N⋅m
c) 46.5 J
d) b and c
e) none of the above
d) b and c
Why does a helium balloon appear to become partially deflated when it is taken outside in winter?
Helium molecules lose energy at lower temperatures and move closer together.
Solve each equation for the unknown variable:
7 = 21/y
y = 3
Describe the relationship among the terms heat, temperature, and thermal energy
Heat is the flow of thermal energy. The greater the thermal energy, the greater the heat, which increases the temperature of a substance.
Methanol is a toxic, colourless liquid. At one time, its freezing point of -97.7°C made it an important component of antifreeze used in the engines of vehicles. However, because methanol boils away at the relatively low temperature of 65°C, it was eventually replaced by ethylene glycol in antifreeze. Referring to both kinetic energy and the postulates of the kinetic molecular theory, explain what happens to the particles in methanol when its temperature reaches -97.7°C.
This is the freezing point of methanol. During this time, the particles start to slow down and and go closer to one another, forming a solid.
Perform the following calculation. Provide your answer with the correct number of significant digits and units:
(0.652 L)[(97.5 kPa)(273.15 K)/(101.325 kPa)(294.15 K)]
0.582 L