Objective 3 Review Physical Science

Question #1 Angela wanted to see how far her toy car could travel when rolled down different ramps. She created 4 different sized ramps and rolled the same car down each ramp 10 times and measured the distances. Why did Angela repeat the investigation 10 times for each ramp? How will Angela know which ramp is the best?

Answer #1 Repeating an investigation several times increases the reliability of the results. Angela can determine which ramp is the best by looking at her data. The ramp that the car traveled the furthest on would be the best ramp.

Question #2 A system is a group of items or parts that work together to perform a job or function. A car is considered a system. What are some of the parts of this system?

Answer #2 Responses might include: -Wheels -Engine -Gears -Seats -Tires -Steering Wheel -Brakes -Battery -Lights -Etc….

Question #3 Is a computer a system? If so, what is its job and what are the different parts?

Answer #3 Yes, a computer is a system because it has different parts that work together to do a job. A computer’s job is to help a person complete a task more easily and to store documents, etc that a person created. The parts of this system include: Monitor, keyboard, mouse, speakers, motherboard, circuits, etc…

Question #4 What is a conductor? What are some examples of a conductor?

Answer #4 Conductors are materials that allow heat, sound, electricity, etc. to flow through it. Conductors are often made of materials such as metals. (iron)

Question #5 What is an insulator? What are some examples of insulators?

Answer #5 Insulators are materials that hold things in and do not allow for flow. Insulators are include items made of cotton, plastic, rubber, paper, etc.

Question #6 What material would be the best to use to remove a beaker full of boiling water off of a hotplate: Wood or metal???

Answer #6 Metals are conductors so they would not be a good choice when removing something hot. Wood is an insulator, so it would not transfer the heat from the boiling water. Wood would be your best choice.

Question #7 What are some examples of a solid, liquid and a gas? What do the molecules look like in each state of matter?

Answer #7 Solids: table, rock, pencil, computer, etc. The molecules in a solid are packed very tightly and hold their shape. They do not take the shape of their container. Liquids: milk, water, soda, oil The molecules in a liquid flow over each other. They take the shape of whatever container that they are in. Gases: oxygen, helium, nitrogen The molecules in a gas are spread apart from each other and are constantly bumping into each other. They too fill the shape of whatever container (or room) that they are in.

Question #8 What are the similarities/differences between mixtures and solutions? What are some examples of each?

Answer #8 A mixture is a combination of two or more ingredients that can be separated by physical means. Examples include: party mix, salad, salt and pepper. A solution is a special kind of mixture. In a solution, one substance dissolves in another substance. The dissolved particles as so small that they cannot been seen even with a microscope. Examples include Kool aid, gatorade

Question #9 Carly went to the movies and purchased a bag of snack mix and a medium lemonade to drink. Of the two items that she purchased, which one contains ingredients that experienced change in their physical properties as they were combined?

Answer #9 The ingredients in the lemonade went through physical changes. The sugar in the lemonade had to dissolved in order for the drink to be sweetened. All of the ingredients in the snack mix are the same as they started out as. Their physical characteristics were not changed.

Question #10 Rick placed 500 mL of water in a beaker. He added 100mL of salt to the beaker and placed it in the window. Over several days, the water was gone but a white layer remained in the beaker. Explain what happened.

Answer #10 The water in the beaker completely evaporated. The white layer left in the beaker is the salt. When water evaporates, whatever is in the water is left behind. Since Rick originally added 100mL of salt into the beaker, there will be 100mL of salt left in the beaker after the water evaporates.

Question #11 List 5 facts that you know about water.

Answer #11 Responses can include: -Water is a liquid -Boiling point is 100 degrees Celsius -Freezing Point is 0 degrees Celsius -It is made of Oxygen and Hydrogen -It covers about 75% of our Earth -Etc…..

What is it called when a liquid changes to a gas? Question #12 What is it called when a liquid changes to a gas?

Changing from a liquid to a gas happens during evaporation. Answer #12 Changing from a liquid to a gas happens during evaporation.

Question #13 What are some items that produce the following forms of energy? Light_____________________________________ Heat_____________________________________ Electrical_________________________________ Solar_____________________________________

Answer #13 Light: lamps, car headlights, flashlights, aquarium lights Heat: stoves, ovens, furnaces, space heaters Electrical: hair dryer, curling iron, fans, washing machines, blenders Solar: solar panels, solar calculators

What are some ways the the Sun interacts with things on Earth? Question #14 What are some ways the the Sun interacts with things on Earth?

Answer #14 Answers can include: -warms the soil -causes sunburn -provides energy to plants -melts ice -heats the oceans

Question #15 What is reflection? What are examples or reflection?

Answer #15 Reflection is the bouncing back of light ray from a surface. Examples of reflection include mirrors, still water in a pond, sunglasses, store windows

What are some examples of refraction? Question #16 What is refraction? What are some examples of refraction?

Answer #16 Refraction is the bending of a light ray as it passes through matter. Light must be transmitted through matter in order for it to be refracted. Examples of refraction are eyeglasses, prisms, magnifying glasses, telescopes

What forms of energy are created from a television? Question #17 What forms of energy are created from a television?

Answer #17 A television creates the following energy forms: -Light energy -Sound energy -Electrical energy -Heat energy

What are some possible reasons why a circuit will no longer work? Question #18 What are some possible reasons why a circuit will no longer work?

Answer #18 Possible problems include: -broken switch -wires connected incorrectly -dead battery -broken filament in the light bulb -loose wire

What is needed for a sound to be heard? Question #19 What is needed for a sound to be heard?

Answer #19 In order for a sound to be heard, you must have: -A vibrating object -A medium for the vibration to travel through -A receiver of the vibration (ear)