Answer:
Proton, neutron, electron
Explanation:
The atom consists of a nucleus, where almost all the mass is concentrated, and electrons orbiting around the nucleus.
The nucleus consists of two types of particles:
- Proton: it has a mass of 
, and a positive electric charge of +e (
)
- Neutron: it has a mass of 
, and it has no electric charge
The third particle that makes an atom is the electron, that orbit around the nucleus:
- Electron: it has a mass of 
, and it has a negative electric charge of -e (
)
watts = work per second.
work is mgh = 3x10x50=1500
watts out = 1500
Watts used = 2000
eff=1500/2000=75%
There are different options here but all of them work by approximating and assuming.
i) that the boulder is above ground.
ii) that the bottom surface of the boulder is known.
iii) the shape of the boulder is taken into account.
The most accurate way is measuring it by displacement method but the boulder is immovable hence the volume can be calculated by measuring the boulder or a waterproof box to be built around the boulder and calculate the volume occupied by boulder.
All the above methods are estimating methods.
*Another way to find the density is through specific gravity.
S.G = <u>Density</u><u> </u><u>of</u><u> </u><u>object</u>
Density of water
If the material that makes the boulder is known that is if it's stone or a mineral then the specific gravity can be found.
If the boulder is purely rock then S.G lies between 3 - 3.5 and the density of water is known thus the density of the boulder can be found without moving the boulder.
This is what I think after correction and allthe best!
measures angular displacement per unit time. Its units are therefore degrees (or radians) per second.
