PLEASE HELP! It’s urgent... and please show your work!!

1. The radius of Earth is 6370000 m. Express this measurement in km in
scientific notation with the correct number of significant digits.
a) 6.37 x 100 km
b) 637 x 103 km
c) 6.37 x 103 km
d) 63.7 X 104 km

Mutt and jeff are running along a path each pushing a cart loaded with rocks. if mutt's wagon has a mass two times greater than jeff's and they want to stay together, arriving at their destination at the same time, what must happen? a) jeff should slow down so mutt can catch up. b) mutt must use half as much force to push his cart. c) mutt must use twice as much force to push his cart. d) mutt and jeff will use the same force, but mutt will take bigger steps.

A3030 cmcm wrench is used to loosen a bolt with a force applied 0.30.3 mm from the bolt. it takes 6060 nn to loosen the bolt when the force is applied perpendicular to the wrench. how much force would it take if the force was applied at a 3030 degree angle from perpendicular? a 3030 cmcm wrench is used to loosen a bolt with a force applied 0.30.3 mm from the bolt. it takes 6060 nn to loosen the bolt when the force is applied perpendicular to the wrench. how much force would it take if the force was applied at a 3030 degree angle from perpendicular?

Dao makes a table to identify the variables used in the equations for centripetal acceleration. what quantities belong in cells x and y?