Show:
Force
Pressure
Fluids
Motion/Weight/Mass
100
What is a force?
A force is a push or pull that acts on an object.
100
What is pressure?
Pressure is the amount of force acting over a given area.
100
What is viscosity?
Viscosity is the resistance of a fluid to flow.
100
How is weight different from mass?
Weight is the amount of force on an object due to gravity. Mass is the amount of matter in an object.
200
What is the difference between contact forces and action-at-a-distance forces?
Contact forces can only have an effect on objects that they touch. Action-at-a-distance forces can apply forces to an object without touching it.
200
What is compression?
Compression is a decrease in volume produced by a force.
200
What is cohesion?
Cohesion is the strength with which the particles of an object or fluid attract each other.
200
What are balanced forces and what effect do they have on the motion of an object?
Balanced forces are equal in strength and oppose each other in direction. Balanced forces can keep an object stationary or be in balance on an object moving.
300
What is the measuring unit of force and who is it named after?
The measuring unit of force is the newton (N); it is named after Sir Isaac Newton.
300
Why are gases easy to compress but not liquids and solids?
Gases are easy to compress because there is a large amount of space between their particles. Liquids and solids are difficult to compress because the particles are already tightly packed together.
300
How is flow rate related to viscosity?
Flow rate is the speed at which a fluid flows from one point to another; the slower a fluid flows, the greater the viscosity.
300
Why is your weight different on different planets?
Your weight is different on different planets because weight depends on gravity and there are different gravities on different planets.
400
Name 3 different action-at-a-distance forces and explain what each is.
1. Gravitational force - The force of attraction between objects because they have mass. 2. Electrostatic force - Static electricity; causes pushing and pulling forces. 3. Magnetic force - Acts on certain metals and compounds, such as iron, nickel, and cobalt.
400
A box is putted on a table. If the box's bottom has dimensions of 50cm by 1m and weighs 650N, what pressure does it put on the table?
P = F/A = 650N/(0.5m x 1m) = 1300N/m2 = 1300Pa = 1.3kPa
400
What is adhesion and why do fluids adhere to certain surfaces?
Adhesion is attraction or joining of two different objects or fluids to each other. Fluids adhere because the polarity of water molecules makes them attracted to certain surfaces.
400
Why does a balance scale work anywhere in the universe?
A balance scale work anywhere in the universe because gravity pulls equally on objects of equal mass and mass stays the same everywhere in the universe.
500
From a newton gauge, 1kg mass is equal to ____N?
9.8 N
500
How will a container explode and how will a container implode? Explain why.
A container will explode when energy(heat) is added because the particles will move faster and increase in pressure. A container will implode if the air pressure outside is greater than the air pressure inside.
500
Why do liquids' viscosity decreases when cooled but gases' viscosity decreases when heated?
Particles in liquids are close together and the attraction between particles causes friction which slows the flow rate. However, gases have more space between particles so the interaction between particles cannot cause much resistance to flow.
500
If an unbalanced force acts on an object, what are four things that could happen to the object?
1.The object could start moving. 2.The object could change direction. 3.The object could speed up. 4.The object could slow down.