Answer:
Helium
Explanation:
Helium is the least reactive element, since it is a noble gas with the smallest amount of valence rings.
Answer:
From question (a) and (b) the pendulum motion is perpendicular to the force so the normal force will do no work and the tension in the string of the pendulum will not work

And
so

c
An example will be a where a stone is attached to the end of a string and is made to move in a circular motion while keeping the other end of the string in a fixed position
d
A dog walking along a surface which has friction, here the frictional force would acting in the direction of the motion and this would do positive work
Explanation:
Explanation:
Sucrose is a disaccharide which is composed of fructose and glucose. Sucrose molecule has oxygen atoms bonded to hydrogen atoms (O-H bonds - Polar groups) on all ends of its double 6-Carbon ring. The areas near the oxygen atoms are slightly negative, and the areas near the hydrogen atoms are slightly positive that is, the O-H bonds are polar. They bond with the neighbouring Oxygen and Hydrogen atoms because of their
dipole - dipole attractions and hence hydrogen bonds are formed.
However, the covalent bonds within the molecule aren't broken. But rather, the hydrogen bonds holding the sucrose molecules in the crystalline lattice.
Answer:
.
Explanation:
The efficiency of a machine is the percentage of energy input that was turned into useful energy.
The power rating of this lamp is
(same as
,) meaning that
of energy is supplied to this lamp every second.
The question states that
out of that
of energy input would be turned into heat, which is not useful energy output in this scenario. Assuming that all other forms of energy loss is negligible. The rest of the
of energy supplied to this lamp would be turned into useful energy output.
Thus, every second, this lamp would receive
of energy input and would outputs
of useful work. The efficiency of this lamp would be:
.
The potential energy of the skateboarder at the top of the ramp is
489.1 J.
<h3>Is kinetic energy always equal to potential energy?</h3>
The amount of kinetic energy change and the amount of potential energy change are equal in all physical processes that take place in closed systems. When the kinetic energy rises, the potential energy falls, and vice versa.
Potential energy is the stored energy in any object or system as a result of its position or component arrangement. However, external factors like air or height have no effect on it. The energy of a moving object or system is referred to as kinetic energy.
Potential energy = kinetic energy
Potential energy = 1/2mv²
Potential energy = 1/2 × 67×7.3
Potential energy = 489.1 J.
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