The formula for this problem that we will be using is:
F * cos α = m * g * μs where:F = 800m = 87g = 9.8
cos α = m*g*μs/F= 87*9.8*0.55/800= 0.59 So solving the alpha, find the arccos above.
α = arccos 0.59 = 54 ° is the largest value of alpha
The last one, handmade gifts require more of the givers time!
Voltage = current(I) * resistance (R)
V = 18
R = 6
18 = I * 6
I = 18/6 = 3 Amps or D
I think that the answer is A
The elements is group 18 on the periodic table are called "Nobel Gases".