Answer:
c. may be accompanied by the sound of explosively expanding hot air, called thunder.
Explanation:
Lightning is a discharge which is due to the reaction between oppositely charged charges in the clouds, or between clouds base and the Earth surface.
The motion of the cloud causes charging of clouds by friction, thus the reaction between opposite charges (jumping of charges from one cloud to another) in the cloud can lead to lightning. Also, oftentimes the bottom of a cloud is negatively charged so that this is attracted to the positive charge on the earth surface. Thus leading to a discharge called lightning.
Thus in the given question, the appropriate option is C. This implies that, lightning may be accompanied by the sound of explosively expanding hot air, called thunder.
Answer:
The weight of measuring stick is 9.8 N
Explanation:
given information:
the mass of the rock,
= 1 kg
measuring stick, x =1 m
d = 0.25 m
to find the weight of measuring stick, we can use the following equation:
τ = Fd
τ = 0
-
= 0
F_{r} = the force of the rock
F_{s} = the force of measuring stick
![F_{s} =F_{r}](https://tex.z-dn.net/?f=F_%7Bs%7D%20%3DF_%7Br%7D)
= m g
= 1 kg x 9.8 m/s
= 9.8 N
thus, the weight of measuring stick is 9.8 N
Explanation:
a) Density is the amount of mass in a specific amount of volume
b) Some substances are less dense than water so will float and vice versa
c) The wooden plank has less density than water due to having larger volume and vice versa with the wooden block since volume and density are inversely proportional
II) (a) They are all metals
(b) water -> Compound
oxygen -> Element
Gold-> Element
Salt-> Compound
Answer:
lipids are insoluble in water which is why lipids are often found in biological membranes and other waterproof coverings.