# Science Chap.15

 What does a ruler measure? distance What kind of surface causes the least friction? Give an example. Smooth surface, you can slide farther on ice than dirt or grass. What 3 things affect an object's motion? - the strength of force- the direction of the force- the mass of the object What kind of object would be affected by a magnetic force? Give an example. Iron and steel. The magnet sticks to a refrigerator. How do scientists figure the speed of a wave? By measuring the wave length If friction did not exist, could Mom drive a car? Why or why not? No, without friction the tires would slide around and you wouldn't go forward or stop. If you and a friend push the same way on a door, what is the net force on the door? What is the net force if equal forces act in opposite directions? The net force on the door equals your friend's push and yours. When equal forces act in opposite directions they cancel each other out, the net force is zero. If you want to conduct an investigation to compare the speed of a dog with the speed of a snail, what could you do to measure their speed? How should you conduct the investigation? Use a stopwatch to measure time and a meter stick to measure distance. Speed is a measure of an object's change in position. Authorcami44 ID150341 Card SetScience Chap.15 DescriptionStudy guide Updated2012-04-26T21:06:10Z Show Answers