Answer:
894 electrons
Explanation:
The electrostatic force between the two charges is given by:

where we have
is the force
k is the Coulomb's constant
q1 = q2 =q is the magnitude of the charge on each sphere
r = 20.0 cm = 0.20 m is the distance between the two spheres
Substituting and solving for q, we find the charge on each sphere:

And since each electron has a charge of

the net charge on each sphere will be given by

where N is the number of excess electrons; solving for N,

Distance in a minute=<span>0.5 times 30=15 meters
distance in a second</span><span>=15 divided by 60=0.25 meters per second
hope it helps</span>
At A, coaster is only associated with potential energy.
At B, coaster is associated with kinetic as well as potential energy.
Since the track is frictionless, no energy will be lost when coaster reaches from point A to point B. Therefore, according to conservation of energy, total energy at A should be equal to total energy at B.
Total energy at A = mgh = mg(12)
Total energy at B = mgh+ mv²/2 = mg(2) + mv²/2
∴12mg = 2mg + mv²/2
∴(12g-2g)×2 = v²
∴v² = 20g
∴v = 14m/s.
Again conserving energy at points B and C.
Total energy at B = 2mg + m(14)²/2
Total energy at C = 4mg + mv²/2
∴2mg + m(14²)/2 = 4mg + mv²/2
Solving this you get,
v = 12.52 m/s.
Therefore, speed of roller coaster at point C is 12.52 m/s.
Answer:
b = 242 m
Explanation:
A = 24200 m²
a = 100 m
b = ?
A seguinte fórmula é aplicada
A = a*b
⇒ b = A / a
⇒ b = (24200 m²) / (100 m)
⇒ b = 242 m