Part a
Answer: 17.58 km/h

Total Distance =10 km
Total time =0.5689 h

Part b
Answer: 17.626 km/h

Total Distance =42.195 km
Total time =2.3939 h

Answer:
K = -½U
Explanation:
From Newton's law of gravitation, the formula for gravitational potential energy is;
U = -GMm/R
Where,
G is gravitational constant
M and m are the two masses exerting the forces
R is the distance between the two objects
Now, in the question, we are given that kinetic energy is;
K = GMm/2R
Re-rranging, we have;
K = ½(GMm/R)
Comparing the equation of kinetic energy to that of potential energy, we can derive that gravitational kinetic energy can be expressed in terms of potential energy as;
K = -½U
Answer:
The formula for calculating force is F= Mass × Acceleration
Explanation:
Newton is what force is measured in
It's a quantitative observation because it includes numerical data.