<h3><u>Answer;</u></h3>
126 joules
<h3><u>Explanation;</u></h3>
Potential energy is the energy possessed by a body while at rest.
It is calculated by the formula m×g×h; where m is the mass, h is the height and g is the gravitational acceleration, 10N/kg
Potential energy = m×g×h
= 3.0 × 4.2 × 10
<u>= 126 joules</u>
Answer:
Explanation:
From the given information:
radius = 15 m
Time T = 23 s
a) Speed (v) =
v = 4.10 m/s
b) The magnitude of the acceleration is:
a = 1.12 m/s²
c) True weight = mg
Apparent weight = normal force
From the top;
the normal force = upward direction,
weight is downward as well as the acceleration.
true weight - normal force = ma
apparent weight =mg - ma
= 0.886 m/s²
d)
From the bottom;
acceleration is upward, so:
apparent weight - true weight = ma
apparent weight = true weight + ma
= 1.114 m/s²
1,2: When simple molecular substances melt or boil, it is these weak intermolecular forces that are overcome. The covalent bonds are not broken. Relative little energy is needed to overcome the intermolecular forces, so simple molecular substances have a low melting and boiling points.
3: Water, Almost no living thing can survive without water. Water is everywhere on our planet. It is the reason we have an organic life on earth. A water molecule consists of one oxygen atom combined with two hydrogen atoms. We use water throughout day and night; in drinking, cooking, household needs, industries, and agriculture. Apart from these general uses of water, you might be amazed to know that water plays a major role in volcanic eruptions.
The light collection of a telescope is proportional to the AREA of the objective lens or mirror. So the 8m collects 4 times as much light as the 4m does in the same time. Or the bigger one collects the same amount of light in 1/4 of the time that it takes the smaller one.
Under the same observing conditions that the 4m needs 3 hours, the 8m monster can do the job in 45 minutes.