Laboratory Flashcards
T OR F
- An object will remain at rest or in uniform motion in a straight line unless acted by an internal force
False (external force) 1st Law of Motion (Law of Inertia)
T or F
An object acceleration is inversely proportional to the force exerted on it. This implies that an object’s acceleration will decrease by the same amount if the force applied is increased
False (directly proportional) (increase)
2nd law of Motion (Law of Acceleration)
Tor F
All objects, regardless of mass, fall to the ground with an acceleration due to gravity of approximately 9.8m/s^2.
True
T or F
Acceleration occurs when there is a change in the speed or direction of an object.
True
Acceleration is a vector quantity that is defined as the rate at which an object changes its distance.
False (velocity)
T or F
When the density of the fluid increases, the pressure reading also increases. This is because pressure in a fluid is directly proportional to the density of the fluid.
True
Denser fluid exerts more pressure because it has more mass in the same volume, which leads to an increase in the weight of the fluid above certain point
T or F
When the gravitational acceleration decreases, the pressure reading increases. This is because the pressure in a fluid is inversely proportional to the product of fluid’s density, and the acceleration due to gravity.
False
(Must be both increases)
(Directly proportional)
- If a person weighs 180 pounds on Earth, he would weigh 30. 85 pounds on the Moon
False (29.85 lbs)
Mass= weight/ gravity
Weight= 18.37 kg x 1.625 m/s^2= 29.85 lbs
T or F
The density of solids and liquids normally increase with decreasing temperature.
True
Density of a fluid has a direct impact on the pressure within the fluid. Changes in density whether due to changes in temperature or other factors , will result in corresponding changes in pressure.
T or F
As altitude increases, air pressure increases. This is because the air is denser at higher altitudes.
False
(Air pressure decreases)
(Air is less dense at higher altitudes)
T or F
Surface tension is the result of adhesive forces between liquid molecules
False (cohesive)
Cohesion- attraction of like substances/molecules
T or F
Dishwashing liquid reduces the friction between the paper and the surface of the water, which make the paper glides faster and easier.
True
The reason is that the dishwashing liquid breaks the surface tension between paper and the water, which rapidly spreads out, reducing the surface tension.
T or F
Paper with pointed tip moves faster due to the smaller surface area to the direction of motion.
True
When the shape of an object allows it to cut through the air more efficiently, less drag is created. The pointed tip of the paper presents a smaller area to the direction of motion, thereby reducing the drag and allowing the paper to move faster.
T or F
The shape of the paper boat can influence its movement on water.
True
Deeper notches or arches might allow for more dishwashing liquid, potentially creating a stronger propulsion effect. However, we should take note that the changes on the movement of the paper is still greatly influenced by the changes in surface tension
T or F
Surfactants are molecules with a hydrophobic head and a hydrophilic tail.
False
(Hydrophilic head)
(Hydrophobic tail)
When a surfactant is added to water, the hydrophilic heads are attracted to the water molecules, while the hydrophobic tails try to avoid them
