Which situation is the BEST example of inertia?
Responses
A An old lady uses a walker and is able to cross the street.An old lady uses a walker and is able to cross the street.
B A rocket thrusts its boosters and lifts off the launching pad.A rocket thrusts its boosters and lifts off the launching pad.
C A rock is thrown vertically up in the air and it falls back to the earth.A rock is thrown vertically up in the air and it falls back to the earth.
D You go down a steep roller coaster and it feels like your stomach is going up into your throat.You go down a steep roller coaster and it feels like your stomach is going up into your throat.
B A rocket thrusts its boosters and lifts off the launching pad.
A roller coaster begins at the top of a hill. If it accelerates at the rate of 2 m/s2
and has a mass of 2000 kg, what net force is acting on it? (F=ma)
Responses
A 0.001 N0.001 N
B 0.5 N0.5 N
C 1000 N1000 N
D 4000 N
The correct answer is C) 1000 N. According to Newton's second law of motion (F=ma), the net force acting on an object is equal to its mass multiplied by its acceleration. Therefore, the net force acting on the roller coaster is given by F = (2000 kg)(2 m/s^2) = 4000 N.
If there are 4 grams of product produced by the chemical reaction, how many grams of reactant were consumed?
Responses
A 0 grams0 grams
B 1 gram1 gram
C 2 grams2 grams
D 4 grams
The correct answer is D) 4 grams. In a chemical reaction, the law of conservation of mass states that mass is neither created nor destroyed. Therefore, the mass of reactants consumed must be equal to the mass of products produced. Since 4 grams of product were produced, 4 grams of reactant must have been consumed.
Jacob floated a long steel sewing needle on a small piece of cork in a glass of water. He noticed that as he turned the glass around, the cork and needle continued to point toward his backyard. Even after he turned the small floating cork around gently, the needle finally pointed toward the backyard. What is the MOST LIKELY conclusion Jacob will draw?
Responses
A There is a large magnet in the backyard.There is a large magnet in the backyard.
B Jacob’s backyard is on the north side of his house.Jacob’s backyard is on the north side of his house.
C The backyard is downhill from where Jacob is standing.The backyard is downhill from where Jacob is standing.
D A gentle breeze is causing the needle to point toward the backyard.
The MOST LIKELY conclusion Jacob will draw is B) Jacob's backyard is on the north side of his house. This is because the needle is pointing consistently towards his backyard regardless of how the glass is turned. This suggests that the needle is aligning itself with the Earth's magnetic field, which is typically oriented towards the north pole. Therefore, Jacob's backyard is most likely on the north side of his house.
Ms. Crawford gave the following instructions to her science class:
• Place an empty water bottle on the table and remove the lid. Carefully pour 10 ml of vinegar into the bottle.
• Open up the mouth of the balloon and have you lab partner spoon 1 teaspoon of baking soda into the balloon.
• Without spilling any of the baking soda, stretch the mouth of the balloon over the mouth of the bottle.
• Turn the balloon completely upright so that the baking soda inside the balloon pours into the bottle with the vinegar. Watch!
The baking soda looked like it dissolved in the vinegar. Sarah and Connor watched as the balloon expanded and filled with a gas. Was this a physical or chemical reaction and why?
Responses
A chemical - gas producedchemical - gas produced
B physical - water bottle got hotphysical - water bottle got hot
C physical - baking soda dissolvedphysical - baking soda dissolved
D chemical - baking soda disappeared
The reaction described in the scenario is a chemical reaction. This is because a new substance is formed in the process, which is the gas produced that fills the balloon. The reaction between the vinegar (which contains acetic acid) and the baking soda (which contains sodium bicarbonate) produces carbon dioxide gas, water, and a salt. The formation of the gas is evidence of a chemical reaction taking place. Therefore, the correct answer is A) chemical - gas produced.
The Smith family is travelling in their car at 50 km/h due east. Mr. Smith is using cruise control to maintain a constant speed. Describe the net force acting on the Smith car.
Responses
A Net force equals zero.Net force equals zero.
B Net forces are unbalanced.Net forces are unbalanced.
C Net force is positive and to the east.Net force is positive and to the east.
D There is no way to determine net force.