Answer: 3.63 km/s
Explanation:
The escape velocity equation for a craft launched from the Earth surface is:
Where:
is the escape velocity
is the Universal Gravitational constant
is the mass of the Earth
is the Earth's radius
However, in this situation the craft would be launched at a height 
over the Eart's surface with a space elevator. Hence, we have to add this height to the equation:
Finally:
Answer:
Explanation:
We need to apply conservation of momentum and energy to solve this problem.
<u>Conservation of momentum</u>
(1)
- m(c) is the mass of stick clay
- m(w) is the mass of the wooden block
- v(ic) is the initial velocity of clay
- V is the final velocity of the system clay plus wood.
<u>Conservation of total energy</u>
The change in kinetic energy is equal to the change in internal energy, in our case it would be the energy loss due to the friction force. Let's recall the definition of work, it is the dot product between force and displacement, Therefore:
We can find V from this equation:
Now, let's put V into the equation (1) and find v(ic)
I hope it helps you!
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Answer:
E. two times the original diameter
Explanation:
Resistance of a wire is:
R = ρ L/A
where ρ is the resistivity of the material, L is the length, and A is the cross-sectional area.
For a round wire with diameter d:
R = ρ L / (¼ π d²)
The two wires must have the same resistance, so:
ρ₁ L₁ / (¼ π d₁²) = ρ₂ L₂ / (¼ π d₂²)
The wires are made of the same material, so ρ₁ = ρ₂:
L₁ / (¼ π d₁²) = L₂ / (¼ π d₂²)
The new length is four times the old, so 4 L₁ = L₂:
L₁ / (¼ π d₁²) = 4 L₁ / (¼ π d₂²)
1 / (¼ π d₁²) = 4 / (¼ π d₂²)
Solving:
1 / (d₁²) = 4 / (d₂²)
(d₂²) / (d₁²) = 4
(d₂ / d₁)² = 4
d₂ / d₁ = 2
So the new wire must have a diameter twice as large as the old wire.
Answer:
No
Explanation:
I don't think the universe has a starting and ending point because the universe is vast and has not been fully discovered. I think that the universe is endless because all of the stars, planets, and galaxy's have yet to be found and the end or start of the universe is also yet to be discovered so I think that the universe could go on forever.
