Answer:
T/√8
Explanation:
From Kepler's law, T² ∝ R³ where T = period of planet and R = radius of planet.
For planet A, period = T and radius = 2R.
For planet B, period = T' and radius = R.
So, T²/R³ = k
So, T²/(2R)³ = T'²/R³
T'² = T²R³/(2R)³
T'² = T²/8
T' = T/√8
So, the number of hours it takes Planet B to complete one revolution around the star is T/√8
Answer:
v = 22.54 mph.
Explanation:
Given that,
Distance moved, d = 200 m
Time, t = 19.8 s
We need to find the runner's average speed.
We know that,
1 mile = 1609.34 m
200 m = 0.124 miles
19.8 seconds = 0.0055 h
So,
Speed = distance/time

So, the runner's average speed is 22.54 mph.
Answer:
D. 4Al + 3O2 → 2Al2O3
Explanation:
Chemical reactions involves the chemical combination of two or more substances called REACTANTS to yield other substances called PRODUCTS. However, in accordance with the LAW OF CONSERVATION OF MASS, the amount of reactants must be equal to that of the products.
To accomplish this, the reaction must be BALANCED. A balanced equation is an equation in which the number of atoms of each element in the reactant side equals the number of atoms in the product side. In this reaction involving Aluminum and Oxygen to give Aluminum oxide as follows:
Al + 02 → Al2O3
A coefficient is used to balance the number of atoms on both sides of the equation as follows:
4Al + 3O2 → 2Al2O3
Answer:
The induced emf is
Explanation:
From the question we are told that
The radius of the circular loop is 
The intensity of the wave is 
The wavelength is 
Generally the intensity is mathematically represented as

Here
is the permeability of free space with value

B is the magnetic field which can be mathematically represented from the equation as

substituting values


The area is mathematically represented as

substituting values


The angular velocity is mathematically represented as

substituting values
Generally the induced emf is mathematically represented as

At maximum induced emf 
So

substituting values
that statement is true
a Third class lever applied when the effort place between the load and the fulcrum.
For example, in a forearm serve
Fulcrum : The elbow
Effort : The effort that putted by the biceps muscle
Load : The arm