Motion, Forces and Types of Interactions
A car slows down from 30 m/s to 10 m/s in 4 seconds. What is its acceleration?
–5 m/s² (negative acceleration, indicating deceleration)
What is the law of conservation of energy?
Energy cannot be created or destroyed, only transformed.
How many daughter cells are produced at the end of meiosis?
Four
What type of reaction involves the exchange of ions between two compounds?
Double displacement reaction.
What factors increase the reaction rate?
High temperature, higher surface area, use of catalyst and higher concentration of the reactant(s).
What does a straight, horizontal line on a position vs. time graph represent?
The object is at rest.
What is convection?
The transfer of heat by the movement of fluids or gases.
During which phase of meiosis do homologous chromosomes separate?
Anaphase I.
What type of reaction involves a hydrocarbon reacting with oxygen to produce CO₂ and H₂O?
Combustion reaction
What role does a catalyst play in a reaction mechanism?
It lowers the activation energy, making the reaction happen faster without being consumed.
How is velocity different from speed?
Velocity includes direction, speed does not.
Which method of heat transfer occurs through space?
Radiation
What term describes the exchange of genetic material between homologous chromosomes during meiosis?
Crossing over
What volume does one mole of any gas occupy at standard temperature and pressure (STP)?
22.4 liters.
What is the term for the minimum energy that colliding particles need to react?
Activation energy
What does the area under a velocity vs. time graph represent?
Displacement.
What type of circuit allows current to flow through only one path?
A series circuit.
Name the enzyme responsible for adding new nucleotides during DNA replication.
DNA polymerase.
How do you determine the molecular formula if you know the empirical formula and molar mass?
Divide molar mass by empirical formula mass to find a multiplier, then multiply subscripts by this number.
In an exothermic reaction, does the energy of the products increase or decrease compared to the reactants?
Decrease
What does the slope of a velocity vs. time graph represent?
Acceleration.
A student lifts a 20 N backpack 2 meters in 5 seconds. What is the power?
8 Watts (Work = 20×2 = 40 J; Power = 40 ÷ 5 = 8 W)
hat type of inheritance involves many genes affecting one trait?
Polygenic inheritance.
A chemical reaction produces 10 grams of product from 8 grams of reactant. Explain, using the Law of Conservation of Mass, why this result suggests an error in the experiment or measurement.
According to the Law of Conservation of Mass, mass cannot be created or destroyed in a chemical reaction. The mass of the products must equal the mass of the reactants. Since the product’s mass (10 g) is greater than the reactant’s mass (8 g), this indicates an error such as: measurement inaccuracies, contamination or additional substances included in the product, or loss/gain of matter from the surroundings.
Why do endothermic reactions feel cold to the touch?
Because energy is absorbed from the surroundings to break bonds, lowering the temperature around the reaction.