Please help me I’ll mark brainless

An unknown substance has a melting point of 1064 ∘c, is insoluble in water, conducts electricity as a solid, and is hard. given these properties, which of the following are possible identities for the unknown substance? check all that apply. view available hint(s) check all that apply. sio2 f2 au kbr

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

The current in a hair dryer measures 11 amps. the resistance of the hair dryer is 12 ohms. what is the voltage?unit: