Potassium is in the most reactive group of elements, the alkali metals, but it's not the most reactive metal within the group. The alkali metals, Group 1A, are the most reactive metals because they have one valence or outer electron. They lose this electron very easily, forming ions with a charge of +1.
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.
Answer:
20.96 h
Explanation:
The perimeter of the track is 2*pi*r = 20pi miles
In 10 hours, car B would have moved 20miles. So, when Car A leaves from point X, car B is 20pi - 20 miles from point X counter-clockwise and car A.
From here, we can express the distance of A from X like this:
xa = 3t
And the distance of B would be:
xb = 20pi - 20 - 2t
The time t where they would passed each other and put 12 miles between them would be the one where xa - xb is equal to 12:
xa - xb = 12
3t - (20pi - 20 - 2t) = 12
5t = 20 pi - 8
t = (20pi - 8)/5 = 10.96 h
Remember to add this value to the 10 hours car B had already been racing:
t = 20.96h
