Answer:
Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.
Explanation:
By Newton's Second Law,
,
where
is the acceleration of the object in 
,
is the net force on the object in Newtons, and
is the mass of the object in kilograms.
As a result,
.
Assume that all other forces on this object are balanced. The net force on the object will be 
. The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.
<h3>What is the
average acceleration of this object?</h3>
.
.
<h3>Apply Newton's Second Law to find the mass of the object.</h3>
.
Answer:
Option (C)
Explanation:
The nuclear energy is defined as a type of energy which liberates either by the process of nuclear fusion or nuclear fission and is mainly used to generate electricity. This energy is stored in the core of an atom (or nucleus).
It is highly effective, cost-effective and there is no emission of greenhouse gases.
But it also has some disadvantages, of which one is that it produces radioactive waste materials, which are difficult to dispose these substances and is also a very expensive method. These materials emit radiations that are harmful to the organisms. So, it is very challenging to dispose these radioactive waste materials.
Thus, the correct answer is option (C).
The first rubber balloon was made by Professor Michael Faraday in 1824, out of two sheets of rubber whose edges were pressed together. Hot air balloonwas the balloon to make the first recorded manned flight. It was made by the Montgolfier brothers and launched on 21 November 1783.
The thermal efficiency of an engine is
where
W is the work done by the engine
Q is the heat absorbed by the engine to do the work
In this problem, the work done by the engine is W=200 J, while the heat exhausted is Q=600 J, so the efficiency of the machine is
