Physics Kinetic Energy Question
The shuttle craft Galileo from the USS Enterprise encounters a Class M planet. Cmdr. Data decides to orbit the plant 100. m above the surface with a speed of 8.00 x 103 m/s. If the mass of the shuttle-craft is 1.00 x 105 kg.
a) Calculate the gravitational potential energy of the shuttle craft. (Text book answer: 9.8 x 107 J)
b) Calculate the bulk kinetic energy of the shuttle craft. (Text book answer: 1.6 x 108 J)
c) calculate the total mechanical energy of the system. (Text book answer: 2.6 x 108 J)
a) I got the same answe using the equation Eg = mgh = 1.00 x 105 kg * 9.8 m/s2 *100.m = 9.8 x 107 J
b) I tried the using the equation Ek = 0.5mv2 and I got an answer of 3.20 x 1012 J
c) I do not know what to do.
Thank you for your time.
Re: Physics Kinetic Energy Question
a) The question is poorly formed as nowhere are we given the gravitational acceleration of the planet or at least it's mass. We need at least one of them in order to be able to calculate the potential energy of the shuttle. You've assumed that it's the same as Earth, i.e. 9.8 m/s. You should at least state that you've made that assumption. If you were given the radius of the planet you could calculate what it's gravitational acceleration is, assuming a zero thrust orbit, but you're not given this either.
Originally Posted by sakonpure6
b) I get the same answer as you do.
c) total mechanical energy is just the sum of potential and kinetic energy.