Newton's 1st Law
Before Mark cuts his spacesuit glove, he floats through space in his spacecraft at a constant speed in a straight line. What is the net force acting on him?
What is 0N (or balanced forces)?
An object will stay in motion unless acted upon by a force (he cut his suit to use the force of air). Net force is no longer 0.
In the formula F=ma, increasing the force applied to an object will have this effect on its acceleration.
Mark was able to increase the amount of pressurized air coming out of his suit (force) and it led to an ________ in acceleration.
What is an increase (direct relationship)?
Increased force- increased acceleration
When gas jets out of the back of Mark’s glove, the gas pushes backward, and Mark moves ________?
What is forward (or the opposite direction)?
Action Force: Mark’s suit pushes the gas backward 200 N.
Reaction Force: The gas pushes Mark’s suit forward 200 N.
If two space thrusters push on Mark in the same direction with forces of 10 N and 15 N, the total net force is this.
What is 25 N?
add together- same direction
subtract- opposite direction
The formula used to calculate the speed of an astronaut moving through space is this.
What is Speed = Distance/Time?
The crew kept saying velocity- this is speed plus direction!
The tendency of Mark Watney or any object to resist a change in its motion is known as this property.
What is inertia?
An object will keep moving in the same direction if it is not restrained in a vehicle that stops.
If an astronaut applies the same 50N push force to a 10 kg pack and a 50 kg equipment box, which object will experience the larger acceleration?
What is the 10 kg pack (smaller mass)?
The commander had a large pack attached to her and did not accelerate as much as Mark would have when he collided with her.
When Commander Lewis grabs Mark in space, how does the force Mark exerts on Lewis compare to the force Lewis exerts on Mark?
A) Mark exerts a stronger force because he is moving.
B) Lewis exerts a stronger force because she has more mass.
C) They exert forces that are equal in strength and opposite in direction.
D) They exert forces that are equal in strength and in the same direction.
What is equal in strength/magnitude and opposite in direction? (C)
Mark would have had more acceleration away from her if she had not grabbed hold of him because he was less mass than her (not wearing a large pack)
If Mark Watney tests how different suit pressures affect his speed, but he keeps his body mass and his suit mass the exact same during every test, his mass represents this type of variable.
What is a constant (or controlled variable)?
IV: suit pressures
DV: speed/acceleration
On a distance vs. time graph, a completely flat, horizontal line segment indicates that the object is doing this.
What is standing still (or at rest / stopped)?
When Mark punctures his suit, pressurized air escapes, causing him to speed up and change direction. These forces acting on him are now classified as ___________ forces.
What are unbalanced forces?
All the forces acting upon Mark no longer equaled ZERO. Once the air ran out, forces became BALANCED again, so inertia kept him moving at a constant speed until Commander Lewis grabbed him.
In an experiment testing how changing force affects an astronaut's acceleration, the force represents this variable (IV, DV, Constant)?
What is the independent variable?
When Mark manipulated how much air was coming out of his suit, he affected his acceleration.
Part 1: A massive space shuttle collides with a tiny space rock. During the impact, does the shuttle collide with more force, less force, or equal force?
Part 2: Will the massive space shuttle or tiny space rock experience the greater acceleration and impact from this collision?
Part 1: What is equal force?
Part 2: What is the tiny space rock?
In a tug-of-war on Mars, Team A pulls left with 430 N and Team B pulls right with 420 N. The overall net force on the rope is this.
What is 10 N to the left?
If Mark Watney travels 120 meters through space in 40 seconds, his average speed is this.
What is 3 m/s?
Mark Watney has a smaller mass than the heavy Hermes spacecraft. Choose the correct statement regarding their inertia and the force needed to move them:
A) Because Mark has less mass, he has less inertia; therefore, he requires less force (air escaping his suit) to accelerate than the Hermes spacecraft (air escaping from an exploded bomb).
B) Because Mark has less mass, he has more inertia; therefore, he requires more force (air escaping his suit) to accelerate than the Hermes spacecraft (air escaping from an exploded bomb).
What is A?
Larger mass- more tendency to resist changes in motion (speeding up, slowing down, or changing direction).
A smaller mass is more likely to accelerate and requires less force to do so.
Calculate the net force needed to accelerate a 100 kg astronaut across space at a rate of 3 m/s2
What is 300 N?
F=ma
Mark Watney has a mass of 100 kg including his suit. The commander has a mass of 200 kg including her jet pack.
When Watney and the Commander collide with equal force in opposite direction, who will accelerate more?
Who is Mark Watney (smaller mass accelerates more even though force is equal/opposite)?
The crew of Hermes needs to reduce the amount of mass on their ship so they can slow their relative velocity to Mark. They test several different changes in mass to see how this affects their acceleration. Identify Independent and Dependent variables.
IV- amount of mass on ship
DV- acceleration
On a distance vs. time graph, a straight diagonal line going upward represents this type of motion.
What is constant speed?
After Mark introduced the force of air from his suit, the air eventually ran out, and he kept moving. He was moving at a constant rate of speed and direction toward the Hermes, and unless they stopped him, he would have kept going!
Mark is not restrained in his spacecraft while it is in constant motion. The spacecraft suddenly accelerates (slows down) and comes to an abrupt stop. Describe Mark's motion as a result.
What is Mark will continue flying forward until he slams into the wall of his spacecraft?
If you double the mass of an object while keeping the pushing force exactly the same, the resulting acceleration will change in this way.
What is cut in half (or decrease)?
If Mark had been carrying more mass, he might not have made it to the Hermes!
When an astronaut sits stationary in a chair on Earth exerting a downward force of 500 N, the chair exerts this force upward on the astronaut.
What is 500 N?
EQUAL and opposite (upward, downward) force.
Mark Watney releases different amounts of pressurized air from his suit and measures how fast he speeds up toward Commander Lewis.
Part 1: Identify the Independent Variable
Part 2: Identify the Dependent Variable
What is the force from pressurized air (independent variable)?
What is the acceleration (dependent variable)?
On a graph, if you analyzed line segment A-B and then identified from the Y-axis that Mark has traveled a distance of 30 meters, and he did this in 10 seconds (Time is on the X-axis), what was his constant speed during this segment?
What is 3 m/s?