Answer:
c. 20 amps.
just divide the watts by the volts
1. Mass number of Lithium-7: 7
Explanation:
- The atomic number of an element is equal to the number of protons inside its nucleus
- The mass number of an element is equal to the number of protons+neutrons inside its nucleus
The nomenclature "Element-X", where X is the number of protons+neutrons, is used to indicate the mass number of the isotope. Therefore, an isotope of LIthium-7 has a mass number of 7.
2. An isotope of lithium-8 contains 5 neutrons
Explanation:
Lithium is the third element of the periodic table, so its atomic number is 3, which means that it has 3 protons.
In this problem, we have an isotope of lithium-8, which means that it has a mass number of 8: so, the sum of neutrons+protons in its nucleus is 8:
where p is the number of protons and n the number of neutrons. However, we also know that for lithium p=3, so we can find the number of neutrons:
Answer: 1350kg/m3
Explanation:
Db = Mb/Vb
900= Mb/Vb
(where Db is the density of the block of wood = 900kg/m3, Mb is its mass and Vb is its volume
Df = Mf/Vf (where Df, Mf and Vf are the density, mass and velocity of the fluid respectively
note that the same mass is involved because the block of wood can only displace its own mass of the fluid
It displaces two-thirds of its own volume in the fluid.
2/3Vf = Vb
Vf = 2Vb/3
Db = Mb/Vb
900 = 2Mb/3Vf
2700Vf = 2Mb
1350Vf = Mb
since Mb = Mf
Df = 1350Vf/Vf
Df= 1350Kg/m3
When some one balance skate board on pipe the potential energy is responsible to make it slide beacause of m mass and g gravity and height thus the skate boarder concieves mgh potential energy and moving on pipe with balancing himself using kinetic enrgy ie;1/2 mv^2 and thus gauning speed ..for illustrating well there is a another example the two wheeeler gets balanced while moving instead of standing idle or stationary ie; kinetic energy is responsible for balancing