Science First & Last Name Period Date Textbook page 26

1a. The standard measurement system used by scientists around the world is the International System of Units. 1b. Problems that might arise if two scientists use different measurement systems but tried to share data is confusion of their work.

2a. The SI unit for length is meter; the unit for mass is kilogram; the unit for volume is cubic meter; the unit for density is kilogram per cubic meter; the unit for time is second; and the unit for temperature is Kelvin. 2b. An estimate for the length of a baseball bat would be _________ cm. An estimate for the mass of a baseball would be ________ g. To determine how close these estimates are measure the length of the bat with a ruler and measure the weight of the baseball with a balance. 2c. To determine the density of a baseball, follow these steps:

1. Use a balance (scale) to measure the mass of a ball. 2. To determine the volume of the ball, immerse the ball into a known volume of water, and measure how much the water level rises. 3. Divide the mass by the volume to calculate the balls density.

3. Given: mass is 50 gram volume = 2 cm x 2 cm x 2cm = 8 cm 3 Find: density Solution: density= mass/volume density = 50 g/8 cm 3 density = 6.25 g/cm 3

4. Given: mass is 50 gram volume = 4 cm x 4 cm x 4cm = 64 cm 3 Find: density Solution: density= mass/volume density = 50 g/ 64 cm 3 density = g/cm 3