Force and experiments

Force and experiments

Open Ended

Type to first initial of your homeroom teacher and today's date

Reliable Experiments

Good experiments have ...

-a testable question

-only one variable changes controls that stay the same

-tested multiple times

Variables

one variable changes, the other variables stay the same for the experiment

In this experiment both plants are given soil, sun, and the same container. Only one gets watered.

Poll

From the past example, what variable are we changing?

• type of plant

• type of soil

Force and Fan carts

When setting up an experiment we can only test one variable at a time. Many variables must stay the same.

Multiple Choice

In our experiment with force and fan carts, we wanted to see the effect of the surface the cart rolled to the amount of time it took to cross the finish line. Which variable were we changing?

• the length of the track the cart had to cross

• The type of fan cart

• the surfaces the cart rolled on (cement, metal, wood, no friction)

Open Ended

In our experiment testing the effects of friction on the speed of the cart. We only changed the surface the cart rolled on. What variables stayed the same?

Testable Question

A question that has one variable and describes how it will affect the results.

• example= Does the type of ball affect how high it bounces?"

Testable Question

Drives our experiments

Multiple Choice

Testable question- one variable and describes how it will affect the results. Which statement is a good testable question?

• Does the size of a ball affect how high it bounces?

• Does the size of the ball, and the type of surface, and the mass of the ball affect how high the ball will bounce?

This is a picture of how to set up your jornal for an experiment.

Notice that there is a place to do multiple trials for the experiment. Remember we do multiple trials for reliability

Multiple Trials

Multiple trials allow us to get reliable results

Multiple Select

Check all that apply. Multiple trials help us ...

• make sure our experiment is reliable

• avoid error in measurements

• have better data

Prediction statement

The prediction statement is written as, "The (Variable we are changing ) will cause (what we are measuring) to....

-example: The surface the fan cart rolls on will affect the amount of time it takes for it to cross.

Multiple Choice

A force is a...

• push or a pull

• push

• movement or no movement

Force is Measured in units called Newtons

Poll

Friction

• is the opposition of movement

• is what we use to make sure or experiment is reliable.

Four different students take turns pushing a large, heavy ball on the school parking lot. What is the best way to determine which student used the most force to push the ball?

Multiple Choice

What is the best way to determine which student used the most force to push the ball?

• compare the sizes of the students

• compare the ages of the students

• compare the distances that the ball rolled

• compare the number of times the ball was rolled

Friction

The opposition of movement. Causes heat. Rub your hands together, the heat is the resistance of one hand sliding past the other.

Multiple Choice

Which block had the least amount of friction?

• wooden block

• wooden block wrapped in metal foil

• wooden block with sandpaper

Open Ended

Why was the friction greater for the blocked wrapped in sandpaper, than for the block wrapped in foil?

Multiple Choice

Which best describes the force of gravity?

• a pulling force

• a pushing force

• a change in mass

• a change in speed

Multiple Choice

What is the unit called that measures force?

• weight

• meter

• Newton

• kilogram

Experiment Time!

Design an experiment

Write the title in your journal

Design an experiment