Salt is a substance because a substance is a material that has constant composition regardless of its source. Salt is the only option that matches this description
Answer:
Tension = 0.012 N
Explanation:
If the black widow spider is hanging vertically motionless from the ceiling above. Then, the weight of the spider must be balancing the tension in the spider web. Therefore,
Tension = Weight
Tension = mg
where,
m = mass of spider = 1.27 g = 0.00127 kg
g = acceleration due to gravity = 9.8 m/s²
Therefore,
Tension = (0.00127 kg)(9.8 m/s²)
<u>Tension = 0.012 N</u>
Answer:
The focal length of a lens is refers to the distance from the center of the lens to the principal foci.
It is an example of rolling friction because balls roll.
Answer is ROLLING