MEX-017 · Gravitation Sample material

Weightlessness and cosmic velocities

The weight of a body and how it changes with acceleration, overload and weightlessness, the first, second and third cosmic velocities and the corresponding trajectories.

Estimated time: 2 h 50 min 3 activities

Learning objective

Distinguish weight from the force of gravity and calculate weight in accelerated motion.
Understand the physical essence of weightlessness — free fall.
Derive the first and second cosmic velocities.
Learn to determine the type of a spacecraft's trajectory from its initial speed.

Expected outcomes

Calculates weight and overload in a lift, on a convex bridge and in a rocket.
Finds $v_1 = \sqrt{GM/R}$ and $v_2 = \sqrt{2GM/R}$ for any planet.
Determines a satellite's speed and period from the orbit height.

Interactive modelNewton's cannon and cosmic velocities

Activities

Lecture
Lecture · 1 h 15 min · required
Problem solving: weightlessness and cosmic velocities
Practice · 1 h 15 min · required
Final test
Test · 20 min · required · pass ≥ 70%

Completion conditions

  • Lecture
  • Problem solving: weightlessness and cosmic velocities
  • Final test — at least 70%