Grade 12 Physics Exit Ticket: Space

Space Exit Ticket

Grade 12 Physics Space Exit Ticket Challenging 20 Questions 14 Views

Classroom Worksheet

Grade 12 Physics Exit Ticket: Space

Space Exit Ticket

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Grade: Grade 12

Subject: Physics

Topic: Space

Time: 20 Minutes

Difficulty: Challenging

Questions: 20

Instructions:
Answer each question in complete sentences or show your calculations where needed. Work carefully and use appropriate physics concepts and units. Questions increase in difficulty.

Skills Practiced:

Space
Physics
Critical Thinking
Problem Solving

1Question

What is the name of the force that keeps planets in orbit around the Sun?

2Question

State Kepler’s First Law of Planetary Motion.

3Question

Define escape velocity.

4Question

Why does an object in orbit around Earth feel weightless even though gravity is still acting on it?

5Question

A spacecraft moves from a lower circular orbit to a higher circular orbit. Does its orbital speed increase or decrease? Explain briefly.

6Question

What is the relationship between gravitational force and distance between two objects according to Newton’s law of gravitation?

7Question

The Moon has less mass than Earth. Why is the Moon’s surface gravity weaker than Earth’s?

8Question

A satellite is in circular orbit. What provides the centripetal force needed for its motion?

9Question

Using Newton’s version of Kepler’s Third Law, what happens to the orbital period of a planet as its average distance from the Sun increases?

10Question

Explain why astronauts on the International Space Station experience microgravity rather than zero gravity.

11Question

A planet has the same mass as Earth but twice Earth’s radius. Compared with Earth, how does its surface gravity change?

12Question

A rock is dropped from rest on a planet with no atmosphere. Ignoring rotation, what determines its acceleration as it falls?

13Question

Why are rockets needed to travel to space, while airplanes are not enough?

14Question

A spacecraft of mass 2.0 × 10^3 kg orbits Earth at a constant speed of 7.5 × 10^3 m/s. Write the expression used to relate orbital speed, orbital radius, and gravitational force for circular motion.

15Question

If the mass of a satellite doubles while it remains in the same orbit, what happens to its orbital speed?

16Question

A satellite is moved farther from Earth. What happens to its gravitational potential energy, and why?

17Question

A student says, 'There is no gravity in space.' Correct this statement.

18Question

Calculate the gravitational force between two 5.0 kg masses separated by 2.0 m. Use G = 6.67 × 10^-11 N m^2/kg^2.

19Question

A planet has a radius of 3.0 × 10^6 m and a mass of 6.0 × 10^24 kg. Calculate its surface gravity. Use G = 6.67 × 10^-11 N m^2/kg^2.

20Question

A probe is launched from a planet with escape velocity v. If the probe is launched with speed 2v, what can you conclude about its motion far from the planet, assuming no atmosphere and no additional forces? Explain using energy ideas.

Answer Key

#	Answer
1	Gravity.
2	Planets move in elliptical orbits with the Sun at one focus.
3	Escape velocity is the minimum speed an object must have to leave a celestial body’s gravitational field without returning, assuming no additional propulsion and ignoring air resistance.
4	It is in continuous free fall around Earth, so both the spacecraft and the object accelerate together and there is no support force.
5	It decreases. Higher orbits have lower required orbital speed because gravity is weaker at larger distances from Earth.
6	Gravitational force is inversely proportional to the square of the distance between the objects, F ∝ 1/r^2.
7	Surface gravity depends on mass and radius. The Moon’s much smaller mass means it produces a weaker gravitational field at its surface.
8	Gravity provides the centripetal force.
9	The orbital period increases.
10	Gravity is still significant in orbit, but the astronauts are in free fall, so they experience very small apparent weight, not zero gravity.
11	It becomes one-fourth as large, because surface gravity is proportional to M/r^2 and the radius is doubled.
12	The planet’s gravitational field strength at that location determines the acceleration.
13	Rockets can produce thrust in space by carrying both fuel and oxidizer, and they can reach the very high speeds needed to overcome gravity and reach orbit; airplanes require air for lift and combustion.
14	Set gravitational force equal to centripetal force: GMm/r^2 = mv^2/r.
15	Its orbital speed does not change, because orbital speed depends on the central body and orbital radius, not on the satellite’s mass.
16	Its gravitational potential energy increases (becomes less negative) because it is farther from Earth and less tightly bound gravitationally.
17	Gravity exists throughout space; objects in space still experience gravitational attraction from planets, stars, and other masses. Spacecraft feel weightless mainly because they are in free fall.
18	F = Gm1m2/r^2 = (6.67 × 10^-11)(5.0)(5.0)/(2.0^2) ≈ 4.2 × 10^-10 N.
19	g = GM/r^2 = (6.67 × 10^-11)(6.0 × 10^24)/(3.0 × 10^6)^2 ≈ 44.4 m/s^2.
20	It will escape the planet and still have excess kinetic energy far away. Since escape velocity is the minimum speed needed to reach infinity with zero final speed, a launch speed of 2v means the probe leaves with positive total energy and will move away indefinitely.