Question

If a rock is thrown upward on the planet Mars, what will happen to its motion?

1) It will continue to move upward with constant speed
2) It will stop moving as soon as it reaches its highest point
3) It will start moving downward with increasing speed
4) It will continue to move upward but with decreasing speed

Answer 1

If a rock is thrown upward on the planet Mars, what will happen to its motion is (1) It will continue to move upward with constant speed.

Step-by-step explanation:

When a rock is thrown upward on the planet Mars, it will experience the force of gravity acting against its upward motion. As the rock ascends, the gravitational force slows it down, causing a decrease in its upward speed. This deceleration occurs due to the gravitational pull of Mars, which is weaker than Earth's but still influential enough to affect the motion of the rock.

While the rock continues to move upward, the decreasing speed indicates that the gravitational force is gradually overcoming the initial upward force imparted to the rock. Eventually, the rock will reach its highest point, where its upward speed becomes zero, marking the peak of its trajectory. Subsequently, the gravitational force will cause the rock to descend, accelerating downward.

Option 1 is correct.

Answer 2

If a rock is thrown upward on the planet Mars It will start moving downward with increasing speed. The correct answer is 3.

Step-by-step explanation:

When a rock is thrown upward on the planet Mars, it experiences the influence of Mars' gravitational force, just like on Earth. The motion of the rock can be analyzed using the laws of physics, particularly Newton's law of gravitation and the equations of motion. Initially, when the rock is thrown upward, it undergoes acceleration due to gravity g. The gravitational force pulls it downward, and as the rock moves against this force, its velocity decreases until it reaches its highest point.

At the highest point, the rock momentarily comes to a stop before reversing direction and starting to fall back toward the Martian surface. As it descends, the gravitational force now aids its motion, causing an increase in velocity. The acceleration due to gravity acts in the same direction as the motion, leading to an increase in speed as the rock moves downward. The entire motion of the rock, from the initial throw to its descent, is governed by the interplay of gravitational forces and the laws of motion.

Mathematically, the motion of the rock can be described by the equations of motion:

`\[ v = u - gt \]`

where:

v is the final velocity,

u is the initial velocity,

g is the acceleration due to gravity,

t is the time taken.

Understanding the forces and applying these equations allows us to conclude that the rock will indeed start moving downward with increasing speed on the planet Mars.