Most likely gravity, because the gravity would pull it off course or wobble.
Answer:
a). 53.78 m/s
b) 52.38 m/s
c) -75.58 m
Explanation:
See attachment for calculation
In the c part, The negative distance is telling us that the project went below the lunch point.
Different layers represent clouds made of gases that condense at different temperatures.
To develop this problem it is necessary to apply the concepts related to Gravitational Potential Energy.
Gravitational potential energy can be defined as

As M=m, then

Where,
m = Mass
G =Gravitational Universal Constant
R = Distance /Radius
PART A) As half its initial value is u'=2u, then



Therefore replacing we have that,

Re-arrange to find v,



Therefore the velocity when the separation has decreased to one-half its initial value is 816m/s
PART B) With a final separation distance of 2r, we have that

Therefore




Therefore the velocity when they are about to collide is 
Answer:
Explanation:
Given
mass of sled =26 kg
coefficient of static friction 
coefficient of kinetic friction 
In order to move sled from rest we need to provide a force greater than static friction which is given by

After Moving Sled kinetic friction comes in to play which is less than static friction

therefore minimum force to keep moving sledge at constant velocity is 18.34 N