Answer:
When balloon moves in the downward direction two forces acts on it.
i) Force exerted by air in the upward direction
ii) Weight
According to newton’s second law of motion:
Sum of forces = Ma
W – F = Ma
Mg – F = Ma …….. (i)
when some of the mass m is dropped and balloon is moving in upward direction with acceleration a/2 then,
F – W = (M-m)a/2
F – (M-m)g = (M-m)a/2
F – Mg + mg = Ma/2 – ma/2 ….. (ii)
Adding equation (i) and (ii)
mg = M(3a/2) – ma/2
m(g + a/2) = M(3a/2)
m = M(3a/2)/(g + a/2)
Answer:
Explanation:
Physicists have found the latter- that matter is made of fundamental particles, the smallest things in the universe. Particles interact with each other according to a theory called the “Standard Model”. ... The electron is, as far as we know, one of the fundamental, indivisible building blocks of the universe
Answer:
Both Democritus and Dalton suggested that matter is made up of atoms. ... Dalton's atomic theory stated that atoms of different elements combine in simple whole-number ratios to form compounds.
Answer:

Explanation:
There is no external force applied, therefore there is a moment's preservation throughout the trajectory.
<em>Initial momentum = Final momentum. </em>
The total mass is equal to

Where,
mass of ship
mass of fuell expeled.
As the moment is conserved we have,

Where,
Velocity of fuel
Velocity of Space Ship
Solving and re-arrange to
we have,



Where c is the speed of light.
Therefore the ship be moving with speed


Fire spreading from a wall to a nearby couch due to radiant heat transfer is an example of heat reflectivity.
<h3>
What is heat reflectivity?</h3>
When sunlight and other light sources strike a material's surface, its reflectance is measured. This number can be used to characterize a surface's characteristics in terms of surface finish. Another name for reflection is reflectivity.
This is a measurement of the amount of energy that material reflects at a specific wavelength. A value between 0 and 1 can also be used to represent reflectivity (or a percentage between 0 and 100).
Sigma and other top businesses have created a range of other forms of heat reflective fabric in the 50 years after the creation of space blankets, including Fabric and aluminum foil laminates, fabric laminates with metalized thin films.
Learn more about heat reflectivity here:
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