Midterm Review Answer Key 2024-2025 PDF

Name __________________________________________ Period _________________ Midterm Review Answer Key 2024-2025 1.​ Define and give an example of a scientific hypothesis. A testable statement; an educated guess; “if” “then” statement 2.​ Define and give an example of scientific l...

Name __________________________________________ Period _________________ Midterm Review Answer Key 2024-2025 1.​ Define and give an example of a scientific hypothesis. A testable statement; an educated guess; “if” “then” statement 2.​ Define and give an example of scientific law. ​ Describes WHAT is happening in the natural world; a logical or mathematical relationship ​ Ex. Newton’s Laws 3.​ Define and give an example of a scientific theory ​ Explaining WHY certain laws and facts and hypotheses exist ​ Ex. Theory of Evolution; Big Bang Theory 4.​ Identify if the statement is part of science or not part of science. yes 1.​ Open to change no 2.​ Biased (Influenced by personal belief) no 3.​ Based on proof no 4.​ Rigid yes 5.​ Observable yes 6.​ Measurable yes 7.​ Repeatable yes 8.​ Made stronger by different lines of evidence no 9.​ Able to solve all problems yes 10.​Testable 5.​ What are the metric prefixes from smallest to largest? ​ Kilo, hecto, deka, BASE, deci, centi, milli 6.​ What do we add to a number to indicate that it is a measurement? ​ unit 7.​ Convert within the metric system. Practice http://tinyurl.com/478cbb42 8.​ Define Independent (experimental) Variable ​ The variable that we are testing/changing  9.​ Define Dependent Variable ​ The data we are collecting to measure the Independent Variable 10.​Define Controlled Variables The variables that must be kept constant (unchanged) so the experiment is valid 11.​Identify the variables in the experiments described below. Circle the Independent variable, put a box around the dependent variable, and underline the controlled variable. a.​ You water three sunflower plants with salt water. Each plant receives a different concentration of salt solution. A fourth plant receives regular water. After two weeks, the height of the plants is measured. All other environmental conditions like the amount of sunlight, air quality, temperature, type of soil, etc. were kept the same for all the plants. b.​ One tank of goldfish is fed the normal amount of food once a day. A second tank is fed twice a day. A third tank is fed four times a day during a six-week study. The fish’s weight is recorded daily. All tanks were of the same size and shape. c.​ You want to test which size of soccer ball is easiest to juggle with your feet. You test a size 3, size 4, and size 5 ball of the same brand. You count the seconds the ball stays in the air for each of the trials. You allow yourself to use both of your feet, knees, and head to juggle the ball. Size 4 is the most common size for soccer leagues. 12.​What do you do if the results of an experiment do not support your hypothesis? ​ Check your variables; check your data; re-test 13.​How many independent (experimental) variables can there be in a valid experiment? ONE 14.​Define Speed ​ How quickly something is moving ​ How far something travels in a certain amount of time 15.​Define velocity ​ Speed + direction 16.​Define Acceleration ​ Change in velocity (change in speed; change in direction)  17.​What is the difference between a positive and negative velocity? ​ Positive - going away, right, up or forward ​ Negative - going back, left, down or backwards 18.​What is the difference between positive and negative acceleration? ​ Positive - speeding up ​ Negative - slowing down 19.​On the graph identify: a) where the object is speeding up b) where the object is slowing down c) where the object is traveling at a constant speed, and d) where the object is stopped. 20.​On the graph above, how fast is the object traveling at 10 seconds? 30m/s 21.​Describe the motion in each position vs time graph below  Constant to the Constant to the left stopped Slowing down to Speeding up to the right the right right 22.​Which section of the graph shows the fastest speed? 110min - 150min 23.​What is happening between times 50-100 minutes? The object or person is going back to its original starting position 24.​Define Net force ​ Total amount of force acting on the object 25.​Define friction ​ Force exerted by a surface as an object moves across 26.​An object is moving to the right. Which direction is the frictional force? left 27.​Define inertia ​ Object resistance to change in motion due to mass 28.​Define momentum ​ How hard it will be for an object to stop → relationship between mass and speed 29.​Is it easier to stop a heavier object or a lighter one? Why? Lighter object because the object will have less momentum  30.​What is Newton’s 1st Law? An object at rest will stay at rest or an object in motion will stay in motion unless acted upon by an unbalanced force (Law of Inertia) 31.​A toy car has a block on top of it. The car suddenly stops. What happens to the block? Why? ​ It will continue moving forward at the same speed due to Newton’s 1st Law 32.​If you increase the force on an object, the acceleration _increases_ 33.​If you use the same force on a less massive object, the acceleration is _increased_ 34.​What are the action/reaction force pairs that affect the balloon? Which one causes the balloon to move? The air pushes on the balloon The balloon pushes on the air ​​ The reaction force causes it to move 35.​Does it matter if the balloon is touching the ground or let go in the air? It does NOT matter 36.​A ball is hit with a bat. How do the forces on a bat and a ball compare? ​ They are equal because of Newton’s 3rd Law Every action has an opposite and EQUAL reaction 37.​Rank the heights of the ramp from highest to lowest kinetic energy.  38.​Circle all of the scenarios where work is being done. a.​ Lifting a book bag off the ground. b.​ Carrying that bag at a constant speed. c.​ Carrying the bag and speeding up to catch your bus. d.​ Carrying your bag and leaning against the wall to catch your breath since you missed the bus. 39.​What force prevents any machine from being 100% efficient? ​ Friction (releases the wasted energy of thermal/heat)