Answer:
a ) 2.68 m / s
b ) 1.47 m
Explanation:
The jumper will go down with acceleration as long as net force on it becomes zero . Net force of (mg - kx ) will act on it where kx is the restoring force acting in upward direction.
At the time of equilibrium
mg - kx = 0
x = mg / k
= (60 x 9.8 ) / 800
= 0.735 m
At this moment , let its velocity be equal to V
Applying conservation of energy
kinetic energy of jumper + elastic energy of cord = loss of potential energy of the jumper
1/2 m V² + 1/2 k x² = mg x
.5 x 60 x V² + .5 x 800 x .735 x .735 = 60 x 9.8 x .735
30 V² + 216.09 = 432.18
V = 2.68 m / s
b ) At lowest point , kinetic energy is zero and loss of potential energy will be equal to stored elastic energy.
1/2 k x² = mgx
x = 2 m g / k
= (2 x 60 x 9.8) / 800
= 1.47 m
The following answers apply;
- Changes in magnetic properties of rock
- Decrease in well water levels
- Increases in radon gas in groundwater
- Foreshocks
These other choices may be good indicators of an imminent volcanic eruption;
Movement of magma
Increase in sulfur dioxide and carbon dioxide ground emissions
1. Changing from solid to a liquid is called melting / fusion and happen
at the melting/ fusion point.
Reason: melting point is a temperature at which a solid melt and converts into liquid by providing heat.
2. Changing from liquid to gas is called evaporation/boiling and happens at the evaporation/boiling point.
Reason. Evaporation is a process in which molecules from surface of liquid convert into gas.
3. Changing from a gas to a liquid is called condensation and happens at the condensation point.
Reason : In condensation process gas particles converts into liquid droplets.
4. Changing from liquid to a solid is called freezing and happens at the freezing point.
Reason : Freezing is a process that convert liquid into soilid state by decreasing temperature of that specific liquid,
Time required : 25.876 s
<h3>Further explanation</h3>
Given
A car weight = 25000 N
Brake force = 628 N
vo= 6.5 m/s
vt = 0(stop)
Required
time to stop
Solution
W = m . g
25000 = m.10
m=2500 kg
Newton's second law
F = m . a
628 = 2500 . a

vt=vo-at(deceleration a=-)
0=6.5-0.2512.t
0.2512.t=6.5
t=25.876 s
That the hydrogen atom was based on the Quantum theory