Earthquakes produce p waves, which are longitudinal waves that travel underground. how do these waves move through the soil and rock?

What determines the amount of inertia an object has

Element with 5protons and 3neutrons

Freya has a mass of 14kg she is running at 1.1m/s to the left when she runs into eric, who is standing still. eric has a mass of 18kg. after the collision, they continue moving together. what is their velocity after the collision. a. 0.48 m/s to the leftb. 2.5 m/s to the leftc. 0.86 m/s to the leftd. 1.4 m/s to the left