Answer:True
Explanation: The mechanical waves need a medium through which to transport energy because the perturbation travels inside of the medium so it needs molecules that connect elastically the displacement of the wave. For example the sound mainly uses the air molecules to transport the energy also the sound can be traveled in solid materials like metal rods.
Answer: B. 44.64 g
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.
Mass of reactants = mass of iron + mass of oxygen = mass of iron + 34.7 g
Mass of product = mass of iron oxide = 79.34 g
As Mass of reactants = Mass of product
mass of iron + 34.7 g = 79.34 g
mass of iron = 44.64 g
Thus 44.64 g of iron was used in the reaction
Answer:
A) 0.50 mV
Explanation:
In this problem, we can think the wings of the bird as a metal rod moving across a magnetic field. So, and emf will be induced into the wings of the bird, according to the formula:
where
is the strength of the magnetic field
v = 13 m/s is the speed of the bird
L = 1.2 m is the wingspan of the bird
is the angle between the direction of motion and the direction of the magnetic field
Substituting numbers into the formula, we find
Answer:
b) 1. Iron, silicates, carbon
2. Water
3. Methane, Ammonia, Carbon Dioxide.
Explanation:
Protoplanetry disk is the disk of gases and clouds of dust that rotates around the newly made star. The temperature of the protoplanetry disk actually determines the type of the planet that is to be formed. Inner part of the protoplanetry disk is closer to the sun thats why it is the hottest and denser part and composed of the materials like Iron, silicates, carbon as they have high melting points. Then comes those materials that exist in the solid form at lower temperatures such as the volatile materials like water. Ater that the protoplanetry disk is made of highly volatile materials that exists in solid from only at low coldest temperatures. So the outer part of the protoplanetry disk is made up of the Methane, Ammonia and Carbon Dioxide.
Answer:
1) energy = 15.6 kWh, 2) total_cost = $ 2.03
Explanation:
1) The energy dissipated is the product of the power and the time of use In a month it was used t = 6.5 h and the power of the toaster is
P = 2400 W = 2,400 kW
energy = P t
energy = 2,400 6.5
energy = 15.6 kWh
using rounding to a decimal
energy = 15.6 kWh
2) The cost of energy is unit_cost = $ 0.13 / kWh
so the total cost
total_cost = energy unit_cost
total_cost = 15.6 0.13
total_cost = $ 2.028
rounding to two decimal places
total_cost = $ 2.03
