DA Corrections

A student wanted to conduct an experiment to see if temperature affected the time it takes for sugar to dissolve in water. Which is the BEST hypothesis for this experiment?

• Will sugar dissolve in cold water?

• Sugar will dissolve faster in hot water than in cold water.

• A thermometer can show the temperature of sugar and water.

• How much sugar will dissolve in cold water compared to hot water?

Some students added sugar to three cups of water. The water in each cup was a different temperature. They stirred each cup of water after adding the sugar. Their data is shown in the table. Amount of Sugar (grams) | Water Temperature (°C) | Time to Dissolve (seconds) 3 | 5° | 45 3 | 30° | 25 3 | 75° | 5 Which of these BEST explains why the sugar dissolved at the rate it did?

• Sugar dissolves faster in water that is warmer.

• Sugar dissolves faster at room temperature.

• Sugar dissolves faster in smaller amounts.

• Sugar dissolves more quickly in water that is stirred.

A group of students tests five different conditions to investigate how salt dissolves in water. Each cup uses the same amount of salt but changes one or more variables: temperature, particle size, or stirring. For each factor below, select the cup that BEST shows how that factor can increase the rate of dissolution. Select ONE correct answer in each row. Which cup is most affected by temperature?

• Cup 1: coarse salt, cold water, no stirring

• Cup 2: crushed salt, hot water, stirred slowly

• Cup 3: table salt, room temp water, no stirring

• Cup 4: crushed salt, cold water, stirred quickly

• Cup 5: table salt, warm water, stirred slowly

A group of students tests five different conditions to investigate how salt dissolves in water. Each cup uses the same amount of salt but changes one or more variables: temperature, particle size, or stirring. For each factor below, select the cup that BEST shows how that factor can increase the rate of dissolution. Select ONE correct answer in each row. Which cup is most affected by agitation?

• Cup 1: coarse salt, cold water, no stirring

• Cup 2: crushed salt, hot water, stirred slowly

• Cup 3: table salt, room temp water, no stirring

• Cup 4: crushed salt, cold water, stirred quickly

• Cup 5: table salt, warm water, stirred slowly

A group of students tests five different conditions to investigate how salt dissolves in water. Each cup uses the same amount of salt but changes one or more variables: temperature, particle size, or stirring. For each factor below, select the cup that BEST shows how that factor can increase the rate of dissolution. Select ONE correct answer in each row. Which cup is most affected by surface area?

• Cup 1: coarse salt, cold water, no stirring

• Cup 2: crushed salt, hot water, stirred slowly

• Cup 3: table salt, room temp water, no stirring

• Cup 4: crushed salt, cold water, stirred quickly

• Cup 5: table salt, warm water, stirred slowly

Which cup demonstrates all three slowing factors?

• Cup 1: coarse salt, cold water, no stirring

• Cup 2: crushed salt, hot water, stirred slowly

• Cup 3: table salt, room temp water, no stirring

• Cup 4: crushed salt, cold water, stirred quickly

• Cup 5: table salt, warm water, stirred slowly

A car traveled a distance of 100 kilometers in 1 hour. The car stopped for 1 h and then traveled an additional 140 km in 2 h. What was the average speed of the car in kilometers per hour over the course of the entire trip, including when the car was stopped?

• 80 km/h

• 60 km/h

• 85 km/h

• 120 km/h

Which object travels at the greater average speed?

• Object 1, because it travels the longer amount of time

• Object 2, because it travels the shorter amount of time

• Object 1, because it travels the greater distance per unit of time

• Object 2, because it travels the shorter distance per unit of time

It takes Lacey and her mom four hours to get to Houston from Dallas when they drive on the highway. Lacey's mom can drive without stopping for bathroom breaks or gas. What can be said about the velocity of their car?

• Distance

• Acceleration

• Speed

• Displacement

• Direction

Two students created the table displayed. Which of the following statements accurately describes the information in the table?

• Student A listed an example of acceleration, and Student B listed an example of speed.

• Both Student A and Student B listed examples of velocity.

• Student A listed an example of speed, and Student B listed an example of velocity.

• Student A listed an example of velocity, and Student B listed an example of speed.