The largest airplane built that has flown more than once is the Ukrainian-built Antonov-225 Mriya. With a length of 85 m and a wingspan of 88 m, the Mriya

(Dream) was designed to carry the space shuttle of the Soviet Union’s space

program. Unloaded, the top speed of Mriya is 236 m/s, at which its kinetic

energy is 9.76 × 109 J. What is it’s mass?

m = 350474 [kg]

Explanation:

In order to solve this problem we must remember the definition of kinetic energy, which can be easily calculated by means of the following equation.

where:

Ek = kinetic energy = 9.76*10^9[J]

m = mass [kg]

v = velocity = 236 [m/s]

Now replacing and solving the equation.

9.76*10^9 = 0.5*m*(236)^2

m = 9.76*10^9 / (0.5*236^2)

m = 350474 [kg]

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.