Types of Forces
This contact force opposes motion between two surfaces sliding past each other.
What is Friction?
Friction always acts in the direction opposite to the relative motion (TEKS 6.7A).
The formula used to calculate average speed from distance and time measurements.
What is Speed = Distance / Time (v = d/t)?
Calculated by dividing total distance traveled by total time elapsed (TEKS 7.7A).
On a distance-time graph, a horizontal straight line indicates this state of motion.
What is At Rest (Zero Speed)?
Distance remains constant over time, meaning the object is not moving (TEKS 7.7C).
Newton's 1st Law states that an object in motion stays in motion unless acted upon by this.
What is an Unbalanced (External) Force?
Known as the Law of Inertia (TEKS 8.7B).
Write the formula equation representing Newton's Second Law of Motion.
What is Force = Mass × Acceleration (F = ma)?
Force is in Newtons (N), Mass in kilograms (kg), Acceleration in m/s² (TEKS 8.7A).
Calculate the net force: A box is pushed Right with 15 N and pulled Left with 5 N.
What is 10 N to the Right?
Net force = 15 N - 5 N = 10 N Right. Unbalanced force causing acceleration rightward (TEKS 6.7B).
Calculate average speed: A runner covers a distance of 100 meters in 20 seconds.
What is 5 m/s?
100 m ÷ 20 s = 5 m/s (TEKS 7.7A).
On a distance-time graph, the slope of the line represents this physical value.
What is Speed (or Velocity)?
Slope = Rise / Run = Distance / Time = Speed (TEKS 7.7C).
Seatbelts prevent passengers from continuing forward during sudden stops due to this physical property.
What is Inertia?
Inertia is an object's resistance to any change in its state of motion (TEKS 8.7B).
Calculate Force: A 10 kg bowling ball accelerates down a lane at 3 m/s².
What is 30 Newtons (30 N)?
F = m × a = 10 kg × 3 m/s² = 30 N (TEKS 8.7A).
When forces acting on an object equal a 0 N net force, the forces are described as this state.
What are Balanced Forces?
Balanced forces produce zero net acceleration and maintain constant motion or rest (TEKS 6.7B).
The key physical quantity that distinguishes velocity from speed.
What is Direction?
Speed is scalar (magnitude only); velocity is a vector including both speed and direction (TEKS 7.7B).
A steeper diagonal straight line on a distance-time graph indicates a ______ speed.
What is Faster (Higher) Speed?
Steeper slope indicates more distance is covered per unit time (TEKS 7.7C).
When a rocket launches, expanding exhaust gas pushes Down, and the rocket moves Up according to this Law.
What is Newton's Third Law of Motion?
For every action force, there is an equal and opposite reaction force (TEKS 8.7B).
If net force remains constant and mass increases, acceleration does this.
What is Decreases?
Acceleration is inversely proportional to mass (a = F / m) (TEKS 8.7A).
This upward support force exerted by a surface supports the weight of an object resting on it.
What is Normal Force?
Normal force acts perpendicular to the contact surface supporting an object (TEKS 6.7A).
The term for the shortest straight-line vector length from an initial position to a final position.
What is Displacement?
Distance is the total path length, while displacement measures overall net change in position (TEKS 7.7B).
A line that curves upward on a distance-time graph indicates this state of motion
What is Acceleration (Speeding Up)?
Curved lines indicate a changing rate of distance over time (acceleration) (TEKS 7.7C).
A swimmer pushes water backward and moves forward. Identify the action and reaction forces.
Action: Hand pushes water backward.
Reaction: Water pushes swimmer forward.
Action-reaction force pairs act simultaneously on different objects (TEKS 8.7B).
Calculate Acceleration: A 50 N net force pushes a 25 kg cart.
What is 2 m/s²?
a = F / m = 50 N ÷ 25 kg = 2 m/s² (TEKS 8.7A).
A non-contact attractive force that exists between any two masses in the universe.
What is Gravity?
Gravitational force depends on the masses of the objects and the distance between them (TEKS 6.7A).
A car travels in a circle at a constant speed of 20 m/s. Explain why its velocity is changing.
What is because its direction is constantly changing?
Because velocity includes direction, turning causes changing velocity (which is acceleration) (TEKS 7.7B).
A graph line goes up to 20 m in 4 s, stays flat for 2 s, then returns to 0 m at 10 s. What is speed during the flat segment?
What is 0 m/s?
Horizontal flat segments represent zero position change (at rest) (TEKS 7.7C).
Describe how Newton's 1st and 2nd Laws act during a roller coaster ride.
1st Law: Riders feel pushed outward on turns (inertia).
2nd Law: Heavier loaded cars require more force to accelerate.
Newton's laws govern all mechanical movements in amusement park rides simultaneously (TEKS 8.7B).
A wagon accelerates at 4 m/s² under 20 N force. If 5 kg of bricks are added, calculate the new acceleration.
Original mass = 20 N / 4 m/s² = 5 kg + 5kg of extra bricks = 10 kg.
New acceleration = 20 N / 10 kg = 2 m/s² (TEKS 8.7A)