Answer:
True
Explanation:
When a star has reached the main sequence stage, hydrogen is converted into helium by nuclear fusion, . Also, the gravity and pressure are balanced because the star does not radiate more heat than it generates. A star usually spends most of its lifetime at this stage.
The Zero Age Main Sequence is the period during the main sequence when a star stops contracting, and begin to fuse hydrogen in its core.
Solution :
Speed of the air craft,
= 262 m/s
Fuel burns at the rate of,
= 3.92 kg/s
Rate at which the engine takes in air,
= 85.9 kg/s
Speed of the exhaust gas that are ejected relative to the aircraft,
=921 m/s
Therefore, the upward thrust of the jet engine is given by

F = 85.9(921 - 262) + (3.92 x 921)
= 4862635.79 + 3610.32
= 
Therefore thrust of the jet engine is
.
This is the upthrust on an object which is placed inside a fluid
This force act upwards and always push upwards
so the correct answer is given as
D. A force within a fluid that pushes upward
this force is always due to pressure difference at two levels of
at lower level since pressure is more that is why the force is upwards and this upthrust is known as Buoyancy
Answer:
Two oxygen atoms
Explanation:
The majority of the oxygen in the air in our atmosphere consists of molecular oxygen (
), which consists of 2 atoms of oxygen, since free oxygen mainly form covalent bonds with other atoms of oxygen.
A small fraction of the oxygen, however, in the ozone form, which consists of 3 atoms of oxygen bond together (
).
Answer:
The length of open-open pipe needed is 6.23 m
The length of open-close pipe needed is 3.11 m
Explanation:
Fundamental frequency for standing wave mode of an open- open pipe is given by

where v is the velocity and L is the length
The length of open-open pipe needed is

Fundamental frequency for standing wave mode of an open- close pipe is given by

The length of open-close pipe needed is
