An ice cube with food coloring is placed in a glass of room temperature water. Dye begins to drop down from the ice cube to the bottom of the glass. Which of the following statements are true. cold dye is more dense than hot dye
particles in cold dye move more slowly and they sink to the bottom
particles in cold dye move more quickly so they sink to the bottom
If the water were heated the dye molecules would spread out more quickly

cold dye is more dense than hot dye

Explanation:

An ice cube with food coloring is placed in a glass of room temperature water. Dye begins to drop down from the ice cube to the bottom of the glass due to the difference in the density of dye in cold and hot water.

The behavior of  food coloring is caused by the density of cold dye and hot dye. The cold dye is more dense than hot dye and food coloring has a slightly higher relative density, than water, so cold dye drop down from the ice cube to the bottom of the glass.

Hence, the correct answer is "cold dye is more dense than hot dye".

(newtons first law)

conservation of momentum law states :

momentum before collision = momentum after collision

momentum p (kg-m/s)= mass * velocity

say moving car=1 000 kg, velocity = 10 m/s then p = 1 000*10= 10 000 kg-m/s

say still car = 2 000 kg, velocity = 0 m/s then p = 2 000* 0 = 0 kg-m/s

total momentum prior to collision = 10 000 + 0 = 10 000 kg-m/s

momentum after collision = 10 000 kg-m/s

mass now = 1 000 kg+2 000 kg = 3 000 kg

10 000 = 3 000 kg* velocity m/s

10 000/3 000 = velocity

3.33 m/s = velocity after collision

an impulse is a force applied over time , momentum is exclusive of external forces and a perfect collision is implied