Answer:11 km/s
Explanation:
Given
Escape velocity at the surface of earth is 11 km/s
Escape velocity is given by
Escape velocity at the surface of earth
--------------------1
If Escape velocity is three times and the radius is also the three times
i.e. 
Answer:
The person going to the highest apartment door.
Explanation:
Since gravitational potential energy, U = mgh where h is the height above the ground. The person with the highest gravitational potential energy would be the person going to the highest apartment door if we assume that their masses are the same.
Answer:
you should sell your skateboards at $240
Explanation:
The price p to sell your skateboards for so that there is neither a shortage nor a surplus is the price that makes equal the quantity of sales and the quantity of supply, so p is equal to:
q (sales) = q (supply)
-3p + 700 = 2p - 500
700 + 500 = 2p + 3p
1200 = 5p
1200/5 = p
$240 = p
Answer:
B) Electrons and protons
Explanation:
Each proton has a positive charge, and each electron has a negative charge. If the atom is electrically neutral, there must be the same number of electrons and protons.
A) and C) are wrong. Neutrons have no charge, so they can't counteract that of the protons or the electrons.
D) is wrong. The atomic number is the number of protons, and the mass number is the number of protons plus neutrons. The neutrons can't counteract the charge of the protons,
Explanation:
When a charged particle describes a circular path in a uniform magnetic field, the charged particle experiences a magnetic force towards the center of circular path, according to Fleming's left hand rule. Therefore the magnetic force and velocity (tangent to circular path) are perpendicular to each other during the circular motion. As the direction of displacement, is the direction of velocity, hence force and displacement are perpendicular to each other.
Therefore work done by magnetic force,
W=Fscos90=0
