Explanation:
q = mCΔT
where q is heat,
m is mass,
C is specific heat capacity,
and ΔT is temperature change.
For the first ball:
2500 J = (100 g) C (90°C − 25°C)
C = 0.385 J/g/°C
For the second ball:
5000 J = (200 g) C (90°C − 25°C)
C = 0.385 J/g/°C
The two metals have the same specific heat, and are likely the same metal (possibly copper or zinc).
Answer: 1.51 km
Explanation:
<u>Coulomb's Law:</u> The electrostatic force between two charge particles Q: and Q2 is directly proportional to product of magnitude of charges and inversely proportional to square of separation distance between them.
Or, 
Where Q1 and Q2 are magnitude of two charges and r is distance between them:
<u>Given:</u>
Q1 = Charge near top of cloud = 48.8 C
Q2 = Charge near the bottom of cloud = -41.7 C
Force between charge at top and bottom of cloud (i.e. between Q: and Q2) (F) = 7.98 x 10^6N
k = 8.99 x 109Nm^2/C^2
<u>So,</u>

Therefore, the separation between the two charges (r) = 1.51 km
An apple falling to the ground is not an example of centripetal acceleration.