Answer:
Magnetism is the force exerted by magnets when they attract or repel each other.
Refraction is the change in direction of waves that occurs when waves travel from one medium to another. Refraction is always accompanied by a wavelength and speed change. Diffraction is the bending of waves around obstacles and openings.
Answer:
a) 16 N
b) 2.13 m/s²
Explanation:
Draw a free body diagram of the tv stand. There are four forces:
Weight force mg pulling down,
Normal force N pushing up,
Friction force Nμ pushing left,
and applied force P pulling right.
Sum of forces in the y direction:
∑F = ma
N − mg = 0
N = mg
The net force in the x direction is:
∑F = P − Nμ
∑F = P − mgμ
∑F = 25 N − (7.5 kg) (10 m/s²) (0.12)
∑F = 16 N
Net force equals mass times acceleration:
∑F = ma
16 N = (7.5 kg) a
a = 2.13 m/s²
Weight is different (but mass is the same)
Water is more dense then air so it sorta holds the rock as it sinks