Unit 1 & 2 Brain Dump

In scientific research, what does a hypothesis represent?

• A confirmed theory

• An initial assumption

• A scientific principle

• A constant

Answer explanation

In scientific terms, a thesis is often considered an educated guess or hypothesis that proposes a potential explanation for a phenomenon, which can be tested through research and experimentation.

Fill in the blank: A law in science is a _______.

• Theory

• Hypothesis

• Description

• Variable

Answer explanation

A law in science is a description of a natural phenomenon that consistently occurs under specific conditions. Unlike theories and hypotheses, which explain or predict, laws summarize observed behaviors.

Which of the following is an independent variable?

• Measured outcome

• Changed factor

• Repeated trial

• Scientific law

Answer explanation

The independent variable is the 'changed factor' in an experiment, as it is the variable that is manipulated to observe its effect on the measured outcome. The other options do not represent independent variables.

Tags

NGSS.MS-PS3-4

In an experiment, the variable that is observed and recorded is the _______.

• Independent variable

• Dependent variable

• Control variable

• Constant variable

Answer explanation

A dependent variable is the measured outcome in an experiment, as it is what researchers observe and measure to see how it changes in response to the independent variable. Thus, the correct choice is 'Measured outcome'.

What does repetition in experiments ensure?

• Accuracy

• Speed

• Creativity

• Simplicity

Answer explanation

Repetition in experiments ensures accuracy by allowing for the identification of consistent results and minimizing the impact of random errors. This leads to more reliable and valid conclusions.

Tags

NGSS.MS-PS1-2

Fill in the blank: Repetition involves _______ multiple trials.

• Ignoring

• Conducting

• Avoiding

• Simplifying

Answer explanation

Repetition involves conducting multiple trials to ensure reliability and accuracy in results. Ignoring, avoiding, or simplifying trials would not align with the concept of repetition.

Tags

NGSS.MS-ETS1-4

Which force opposes the motion of objects?

• Gravity

• Friction

• Inertia

• Momentum

Answer explanation

Friction opposes motion, so its opposite is motion itself. While friction resists movement, motion indicates the presence of movement, making it the correct answer.

Complete the sentence: To move forward, you must exert a force that is _______ to the direction you want to go.

• Opposite

• Parallel

• Perpendicular

• Identical

Answer explanation

Equal and opposite forces indicate that when you push back, you create a forward motion. This principle is evident in actions like walking, where pushing against the ground propels you forward.

Tags

NGSS.HS-PS2-1

What does the formula D = S x T represent?

• Distance = Speed x Time

• Density = Mass x Volume

• Force = Mass x Acceleration

• Energy = Power x Time

Answer explanation

The formula D = S x T represents the relationship between distance (D), speed (S), and time (T). It shows that distance is calculated by multiplying speed by time, making 'Distance = Speed x Time' the correct choice.

Tags

NGSS.MS-PS3-1

Fill in the blank: In the formula D = S x T, D stands for _______.

• Density

• Distance

• Duration

• Diameter

Answer explanation

In the formula D = S x T, D represents Distance, as it is calculated by multiplying Speed (S) by Time (T). Therefore, the correct answer is Distance.