Which best explains how thermal energy is transferred when someone holds a hand above a fire?

It is transferred by conduction and radiation.
It is transferred by only convection.
It is transferred by only conduction.
It is transferred by radiation and convection.

What property is a characteristic of a substance that can be observed and does not change the identity of the substance

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?

What is the weight of a 8-kg substance in n, kn, kg·m/s2, kgf, lbm·ft/s2, and lbf?