The correct answer is I disagree. Elements form all pure substances, but some pure substances include elements bonded together to form molecules and compounds.
Elements are pure substances but these elements also make other things such as water. The water molecule is made of two elements called oxygen and Hydrogen. Now water itself is a pure substance as it is chemically bonded hydrogen and Oxygen but it is composed of more than one element
wavelength =wavevelocity
--——————
Frequency
Frequency = 1/T => 1 / 6.73 = 0.1486
Wave velocity = L/T => 3.75 / 6.73 = 0.5572
Therefore, wave length = 0.5572/0.1486 = 3.75m
Answer:
The two forces acting on a boat or some other floating object are buoyancy and gravity
Answer:
Spinning permanent magnets within an array of fixed permanent magnets.
Explanation:
Any relative motion between magnets (be they permanent or electromagnetic) and a coil of wire will induce an electric current in the coil.
What will not induce an electric current is the relative motion between the two coils of wire (because there is no change in magnetic field), or the relative motion between two magnets (there are no coils of wire to induce the current into).
Therefore, spinning permanent magnets within an array of fixed permanent magnets does not induce an electric current.
<em>In all other choices, coils of wire are there to be induced current into, and magnets are present to create changing magnetic fields. </em>
Answer: 
Explanation:
Given
mass of sled m=5 kg
Elevation 
(coefficient of kinetic friction)
Friction will oppose the motion of the sled while sled weight sin component helps it to move down the incline
Substituting values
