Newton's Laws
What is the formula to find force? (newton's second law)
f=ma
What is a dependent variable?
The variable that is AFFECTED by something in the experiment
What are controlled variables?
Things that the scientist keeps the same. If they were not kept the same, they may affect the dependent variable and make our results meaningless
What are balanced forces? What are unbalanced forces?
Unbalanced- net force does not = 0
What units are used in the SI system? (name at least 3)
meter, liter, gram, kelvin
What is Newton's first law of motion? (the name of it and what that means)
inertia- an object at rest will stay at rest and an object in motion will stay in motion unless acted on by an unbalanced force
What is an independent variable?
The part of the experiment that the scientist is changing
A student wants to determine the effect of soil type on plant growth. What are the independent and dependent variables?
IV- soil type
DV- plant growth
True or false:
An unbalanced force will always cause a change in speed, direction, or both
What is the goal of the engineering design process?
Find the mass of this object. When a force of 1.29 N is applied, the acceleration is 1.6.
0.8 kg
Density is mass per unit of volume. What are some instruments that could be used to measure density.
(hint: you need something to measure mass and something to measure volume)
A balance/scale and a graduated cylinder
A student wants to determine the effect of soil type on plant growth. What are the controlled variables they should have? Name at least 3
Amount of water, amount of sunlight, how much soil, etc
What is the unit used to measure force?
Newtons (N)
In a displacement graph, what represents fast movement?
I will draw a graph, point out the spot where the person is moving fastest
The most sloped part of the graph represents the fastest movement
If the mass of an object is 20kg and it accelerates 3 m/s^2, what was the force applied?
60 N
What is a controlled experiment?
An experiment where all variables except for the IV and DV are kept constant.
A SINGLE VARIABLE is being tested
The scientific method is an iterative process. What does iterative mean?
Iterative means a repeated process.
"Science circles back on itself so that useful ideas are built upon and used to learn even more about the natural world"
Draw a force diagram to represent a tennis ball falling through the air (with air resistance). The ball is speeding up
picture
Why can't an IV or DV also be a CV?
IV and DV must change, CV can not change
List all three of newton's laws in order
1- inertia
2- f=ma
3- every action has an equal and opposite reaction
When a scientist finds evidence that disputes a currently accepted theory, what should other scientists do?
Run more experiments to help confirm or deny the new theory
What is a peer-reviewed article?
An article that is reviewed by peers (other scientists) before it is published. These sources are trustworthy.
Is the force of friction greater when an object is moving or when an object is not moving
Not moving