What is a star's main fuel during its lifetime? A. hydrogen B. carbon C. helium D. oxygen

1 answer:

6 0

<span>The star's main fuel during its lifetime is hydrogen. It is said that a star is composed of 97% hydrogen and 3% helium. Once the hydrogen of a star is gone, the star becomes old because it burns hydrogen during its lifetime.</span>

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A stuntman of mass 48 kg is to be launched horizontally out of a spring-

Damm [24]

The velocity of the stuntman, once he has left the cannon is 5 m/s.

The right option is O A. 5 m/s

The Kinetic energy of the stuntman is equal to the elastic potential energy of the spring.

<h3 /><h3>Velocity: </h3>

This is the ratio of displacement to time. The S.I unit of Velocity is m/s. The velocity of the stuntman can be calculated using the formula below.

⇒ Formula:

mv²/2 = ke²/2
mv² = ke².................. Equation 1

⇒ Where:

m = mass of the stuntman
v = velocity of the stuntman
k = force constant of the spring
e = compression of the spring

⇒ Make v the subject of the equation

v = √(ke²/m)................. Equation 2

From the question,

⇒ Given:

m = 48 kg
k = 75 N/m
e = 4 m

⇒ Substitute these values into equation 2

v = √[(75×4²)/48]
v = √25
v = 5 m/s.

Hence, The velocity of the stuntman, once he has left the cannon is 5 m/s.

The right option is O A. 5 m/s

Learn more about velocity here: brainly.com/question/10962624

6 0

2 years ago

An hydrogen molecule consists of two hydrogen atoms whose total mass is 3.3×10−27 kg and whose moment of inertia about an axis p

dlinn [17]

Answer:

$6.9631\times 10^{-11}\ m$

Explanation:

I = Moment of inertia = $4\times 10^{-48}\ kg m^2$

m = Mass of two atoms = 2m = $3.3\times 10^{-27}\ kg$

r = distance between axis and rotation mass

Moment of inertia of the system is given by

$I=mr^2\\\Rightarrow I=2mr^2\\\Rightarrow 4\times 10^{-48}=3.3\times 10^{-27}\times r^2\\\Rightarrow r=\sqrt{\frac{4\times 10^{-48}}{3.3\times 10^{-27}}}\\\Rightarrow r=3.48155\times 10^{-11}\ m$