The net force of the object is equal to the force applied minus the force of friction.
Fnet = ma = F - Ff
12 kg x 0.2 m/s² = 15 N - Ff
The value of Ff is 12.6 N. This force is equal to the product of the normal force which is equal to the weight in horizontal surface and the coefficient of friction.
Ff = 12.6 N = k(12 kg)(9.81 m/s²)
The value of k is equal to 0.107.
Given :
The focal length of a concave mirror is 18 cm.
To Find :
The radius of curvature of the concave mirror.
Solution :
We know,

Therefore, the radius of curvature of concave mirror is 36 cm.
Hence, this is the required solution.
Answer:
Peer Review
Explanation:
When scientist check other scientists the process is dubbed "peer review".
Classics.
Resistance is equal to relation between voltage and current.

If we express current:

If current is in fact 0 then one of the quantities either voltage or resistance must be equal to zero. Since resistance cannot be equal 0, because that would violate mathematical law that states that division by zero is undefined the only logical conclusion is voltage.
So the answer should be C voltage and B zero.
Hope this helps!
Base in your questions that ask what cause the bright lines seen in the emission spectrum and i think the best answer to that is the H2 gas is used when protons was heated so the electron absorb all the photons and get exited and resulted by given of a light.