An astronaut measured the surface gravity of a planet to be 5.77 m/s2. If
its radius is 4.17 x 106 m, what is the
mass of the planet?
[?] x 10 kg

Could someone me find the answer to this problem.

Polly is pushing a box across the floor with a force of 30 n. the force of gravity is –8 n, and the normal force is 8 n. which value could describe the force of friction if polly could not move the box?

Which of the following is the main energy source for the sun? a. fission of hydrogen b. fusion of hydrogen c. fusion of helium d. fission of iron