States of Matter
When a substance changes directly from a solid to a gas.
Sublimation
This physical phenomenon is defined as the resistance to flow.
What is viscosity?
How is density calculated?
mass / volume.
What is a force?
Any interaction that will change/alter the motion of an object.
Pressure is measured in...
Pa (pascals)
When a substance changes from a liquid to a solid.
What is solidification?
If a substance is very "thick," then what can we conclude about its viscosity?
It has a high viscosity.
A substance has a mass of 15.0 g and a volume of 3 cm3. What is its density?
5 g/cm3
An object is placed in very salty water. The object floats above the surface. What can we conclude about its weight and buoyancy?
The buoyant force is much stronger than the object's weight?
How can pressure be calculated?
P = F / A
A substance is in its gaseous phase. It begins to lose energy and change into a liquid. What is this process called?
Condensation
If a substance is "runny," then what can be said about its viscosity?
Given a substance's density and its volume, how can mass be determined?
mass = density x volume.
On the Moon, your weight is 1/6th of what it would normally be on Earth. Suppose someone is 180 lbs (pounds), what would this person weigh on the Moon?
30 lbs (pounds)
Without changing the force, how can the pressure be reduced?
By increasing the area.
Explain the difference between evaporation and boiling.
Boiling is a rapid change from liquid to gas, but evaporation is much more gradual.
Given water, honey, yogurt, and melted ice cream, which has the lowest viscosity?
A substance has a density of 3.6 g/cm3 and a volume of 10 cm3. What is its mass?
36 grams.
Cruise ships are made of steel, which is much denser than water. They also weigh over 60,000 tons. One would expect such an object to sink. How is it possible that such an object can float, and what is this phenomenon known as?
If the object can displace a large volume of water, this can increase the buoyant force acting up against the ship. If the buoyant force can be increased high enough to counteract the weight, the ship will float. This is known as Archimedes' principle.
A pressure of 1200 Pa applied to an area of 0.25 m2 will result in a force of...
[You must include the units as well!]
300 N
At the particle level, explain how kinetic energy allows a substance to change from its solid phase to the liquid phase to the gaseous phase.
Increasing kinetic energy will cause the particles to move faster which results in an increase in temperature. This will cause the substance to change from solid to liquid to gas.
True or false:
A high flow rate indicates a high viscosity.
False:
A high flow rate indicates a low viscosity (since it is very "runny")
Larger objects will always have a greater mass than smaller objects.
False:
Neutron stars are much more massive than the Earth, but also much smaller too.
Explain the difference between mass and weight.
Weight is a force, which will vary depending on location and gravity, whereas mass describes the amount of substance that is present. Mass is always the same regardless of location and gravity.
What is the main difference between a hydraulic system and a pneumatic system?
A hydraulic system transmits forces through a liquid, whereas a pneumatic system transmits forces through a gas.