Answer:
<em>The block hits the ground at 27.9 m/s</em>
Explanation:
<u>Gravitational Potential Energy (GPE)</u>
It's the energy stored in an object because of its height in a gravitational field.
It can be calculated with the equation:
U=m.g.h
Where m is the mass of the object, h is the height with respect to a fixed reference, and g is the acceleration of gravity or 
.
When the block is at the edge of the cliff it has potential energy that can be transformed into any other type of energy as it starts falling to the ground.
The GPE of the block of mass m=42 Kg at h=40 m is:
U = 42*9.8*40
U = 16,464 J
The block loses 81 J due to air resistance, thus the energy stored when it hits the ground is 16,464 J - 81 J = 16,383 J.
This energy is stored as kinetic energy, whose formula is:
Solving for v:
v = 27.9 m/s
The block hits the ground at 27.9 m/s
A) Pure substances, Chemical changes
Answer:
The value is 
Explanation:
From the question we are told that
The slit separation is 
The distance of the screen is 
The order of fringe is n = 7
The path difference is 
Generally the path difference is mathematically represented as
=> 
=> 
=>
=> 
=>
Answer:
Explanation:
Absolute zero in the Kelvin scale = -273.15 °C
Temperature difference in the boiling and freezing point
Change in 21.5°C = Change of 100°C in M
Difference in the Celsius scale
Change in 
corresponds to
Therefore the absolute zero in the Methane scale is
Answer:
Using
Period ( P) is given as
P~√(L/g).
a) since mass has no effect on the period of a pendulum. So, the period will remain 1.8seconds
b) using the formula above ,period varies with the square root of the length. Thus , when the length doubles, the period is multiplied by √2. So, the period is 1.8s*√2 = 2.54s
c) in this case, the period is multiplied by √(1/2).
1.8√(1/2)=1.27s.
d) amplitude of the pendulum doesn't affect the period (unless itsvery high, so, the period is still 1.8s
