Any moving object in space will travel in a straight line at the same speed forever, planets included. The planets would be moving in straight lines, but the sun's gravity pulls them toward it. The force of gravity causes the moving planets to travel in roughly circular orbits around the sun.
Answer:
The work done by the force on the particle is 29.85 J.
Explanation:
The work is given by:

Where:
x₁: is the lower limit = 0 m
x₂: is the upper limit = 1.9 m
Fₓ: is the force in the horizontal direction = (4.5 + 13.7x - 1.5x²)N

Therefore, the work done by the force on the particle is 29.85 J.
I hope it helps you!
ಠ_ಠ Hey, hang on.. you might've made a discovery. Nobody has tested it so how do we know? ಠ_ಠ
Its C. a decrease in the radius and an increase in the tangential speed ,I'm 100% sure
<h2>
Spring constant is 6.73 N/m</h2>
Explanation:
For a spring mass system we have
Mass x Acceleration due to gravity = Spring constant x Elongation
mg = kl
Mass, m= 0.454 kg
Acceleration due to gravity, g = 9.81 m/s²
Spring constant,k = ?
Elongation, l = 0.662 m
Substituting
0.454 x 9.81 = k x 0.662
k = 6.73 N/m
Spring constant is 6.73 N/m