While spinning at 50 rad/s, a solid uniform disk has a rotational kinetic energy of 4.5 kJ. If the radius of the disk is 1.3 m, what is its mass, in kg?

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles