Mass and Weight

Mass

Mass and weight are not the same
Mass is the amount of matter in an object and is measured in kilograms
Mass has the same value everywhere
Measured in grams and kilograms

Gravity

  • Altitude/depth
  • Latitude

Weight

w = m\cdot g

Density

\rho=\frac{m}{v}

Volume

definition: the amount of space a object takes up
Sphere: V=\frac{4}{3}\pi r^3
V = \frac{\pi h (D^2+d^2+Dd)}{3}

Measurement

water displacement method

  1. put it on the balance to find mass(m_1)
  2. put some water (V_1) in a measuring cylinder
  3. carefully submerge the object in the water. (Completely submerge it.)
  4. Measure the new reading of the water (V_2)
  5. Use V_2-V_1 to calculate the volume of the object
  6. using \rho=\frac{m}{V}

Pasted image 20240829091247
1. it tells me how weigh it is in a specific volume
2. \rho=\frac{m}{v}
3. True
4. \rho=\frac{m}{v}=\frac{7\space g}{14\space cm^3}=0.5\space g\cdot cm^3
5. v = 4cm\times 5cm\times 3 cm=60cm^3
m=\rho v = 60\space cm^3\cdot 2\space g/cm^3 = 120\space cm^3