Your Question:
<span>A
star is born when gas and dust from a nebula become so dense and hot
that nuclear fusion starts. Which of the following forces is responsible
for the formation of a star?
A.
friction
B.
gravitation
C.
magnetism
D.
electromagnetic energy</span>
Our Teams Answer: B. Gravitation
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-ExperimentsDIY
When you heat something of cool it down you don't change the substance you might change the why is looks, but it is still the same substance. For example you cool water to 0 degrees Celsius it turns into ice but it still is two parts hydrogen and one part oxygen H2O. Physical changes will change state and/or form but it will still be what it originally was on the molecular level. Hope that helped.
Answer:
102000 kg
Explanation:
Given:
A total Δν = 15 km/s
first stage mass = 1000 tonnes
specific impulse of liquid rocket = 300 s
Mass flow rate of liquid fuel = 1500 kg/s
specific impulse of solid fuel = 250 s
Mass flow of solid fuel = 200 kg/s
First stage burn time = 1 minute = 1 × 60 seconds = 60 seconds
Now,
Mass flow of liquid fuel in 1 minute = Mass flow rate × Burn time
or
Mass flow of liquid fuel in 1 minute = 1500 × 60 = 90000 kg
Also,
Mass flow of solid fuel in 1 minute = Mass flow rate × Burn time
or
Mass flow of solid fuel in 1 minute = 200 × 60 = 12000 kg
Therefore,
The total jettisoned mass flow of the fuel in first stage
= 90000 kg + 12000 kg
= 102000 kg
Answer:550N
Explanation:
mass=1100kg
Acceleration=0.5m/s^2
Force=mass x acceleration
Force=1100 x 0.5
Force=550N