How massive is a rocket that accelerates at 40 m/s/s with a force of 1200 Newtons?

30kg

Explanation:

a = 40ms^-2

f = 1200N

f= m×a

1200= 40 × m

= 30kg

1. (1.2kw)x(15/60hours) = .3kwh --> a

2. (5kw)x(90/60hours)x(8cents/kwh) = $0.60 --> d

3. microwave --> 1200 watts = (1.2kw)x(6/60hours) = .12kwh

coffee-maker --> 900 watts = (.9kw)x(10/60hours) = .15kwh

therefore, it requires more energy for the coffee-maker to do the same amount of work.

so the answer is a.