Answer:
điện giữa chúng s
Explanation:
viscous, flammable, hard, malleable
2. At room temp., a substance with a melting point of 40% C is a?
solid, liquid, gas, mixture
3. what action involves a chemical change?
making ice cubes,adding sugar to tea, cutting wrapping paper, baking a cake
4.a substance that has a little tendency to change into other substance is said to have low?
reactivity, viscosity, density, conductivity
5. formation of a precipitate is usually evidence of?
the separation of a mixture, a chemical change, formation of a mixture, physical change
Air pressure
c) What is the magnitude of the contact force on the student by the ground?
Answer:
Explanation:
a) The magnitude of the net force on the student = 0 N since the student is standing still on level ground and upward reaction force = downward force.
b) the magnitude of the contact force on the student by the backpack = 80 N since the student was backing the backpack
c) the magnitude of the contact force o the student by the ground = 550 N + 80 N = 630 N reactional force on the student