Kinematic
Define distance and give one everyday example
Distance is how far an object travels (a scalar). Example: walking 3 km from home to the store.
State Newton's First Law (law of inertia) in one sentence.
An object stays at rest or keeps moving at the same speed and direction unless a net external force acts on it.
State Bernoulli's principle in one sentence.
Where a fluid (air) moves faster, the pressure is lower (along a streamline).
What is torque and what is the simple formula for it?
Torque measures how strongly a force makes something rotate. Simple formula for a perpendicular force: τ=rF, or τ=rFsinθ
Name the independent, dependent, and two controlled variables when testing how launch angle affects range.
Independent: launch angle. Dependent: range. Controlled: initial speed, projectile mass (also launch height).
Define speed and write its units.
Speed is how fast something moves (distance per time). Units: metres per second (m/s) or kilometres per hour (km/h).
Give a simple real-life example of Newton's Second Law and name the parts (force, mass, acceleration).
Answer: Pushing an empty shopping cart vs. a full one — same push force gives a bigger acceleration to the empty cart (Force = push, Mass = cart + contents, Acceleration = resulting change in speed)
In simple terms, what is the Coandă effect?
It's when a stream of fluid (air) tends to follow a nearby curved surface.
A wrench applies 25 N at the end of a 0.3 m handle at right angles. Calculate the torque.
τ=0.3×25=7.5 Nm
How do repeated trials and averaging help an experiment?
Reduce random error; average gives a better estimate; report spread (range or standard deviation).
An object moves with constant speed of 5 m/s for 6 s east, then turns and moves west at 3 m/s for 4 s. Calculate the total displacement (include direction).
Displacement east = 5×6=30 m east. Displacement west = 3×4=12 m west. Net displacement = 30−12=18 m east.
A net force of 12 N12 N acts on a mass of 3 kg3 kg. What is the acceleration? Show work.
a=f/m=12/3=4 m/s2
Name two features of a wing that help make lift and which idea (Bernoulli or Coandă) they relate to."
Cambered top surface — speeds up air over top (Bernoulli). Curved shape — directs air downward (Coandă).
What are the two conditions for static equilibrium?
Net force = 0
and Net torque = 0
Given Time (s): 0,1,2,3 and Position (m): 0,1.8,3.7,5.6 — how do you get velocity from a graph?
Plot position vs. time; slope = velocity (use slope between points or best-fit line). Uncertainties: timing and position measurement errors.
A toy car starts from 15 m/s and decelerates uniformly at 2 m/s2 for 5 s. What is its final speed?
v=u + at = 15 - 2*5 = 5 m/s
Explain action–reaction pairs when you jump off the ground.
You push the ground down (action); the ground pushes you up (reaction). The forces are equal in size and opposite in direction but act on different objects.
Explain two ways pilots can increase lift during takeoff when the airplane is moving slowly. For each method, say why it increases lift in simple terms (use Bernoulli or the Coandă effect where appropriate).
Tilting the wing so it meets the airflow at a steeper angle makes the airflow turn downward more strongly (Coandă effect / change in momentum), producing a larger upward reaction force (more lift). Method 2 — Use flaps to change the wing shape and increase camber. Why: Flaps increase the curvature of the wing so air moves faster over the top surface and the pressure difference between top and bottom grows (Bernoulli), producing more lift at low speeds.
A seesaw is balanced on a pivot. A 4 kg child sits 2.0 m to the right of the pivot. Where must a 6 kg child sit on the left side (how many meters from the pivot) to balance the seesaw? Show work.
For balance, clockwise torque = counterclockwise torque. Torque = mass × distance (g cancels).
torque on one side : 4×2.0=8
Solve for r: r × 6 = 8 , r = 8/6 = 1.3 (m)
So the 6 kg child must sit 1.3 m from the pivot on the left side.
Briefly outline an experiment to test how mass affects acceleration with a constant force.
Materials: low-friction cart, masses, constant launcher, track, timer. Procedure: keep force same, change mass, measure acceleration (repeat). Data: mass vs. average acceleration. Analysis: plot acceleration vs. mass (or vs. 1/m); check that acceleration decreases as mass increases.
A toy car starts from rest and accelerates uniformly at 2 m/s2 for 5 s. Calculate the total displacement during those 5 seconds. (Use s=v0t+1/2at2)
s=0×5+1/2(2)(52)=1×25=25 m.
A person standing on ice throws a heavy medicine ball forward. Describe what happens to the person and explain this using Newton's Third Law. Which direction does the person move and why?
When the person throws the medicine ball forward, the ball exerts an equal and opposite force on the person backward. As a result, the person will move backward (slide backward on the ice).
Quick experiment to show Coandă effect with household items (materials and short procedure).
Materials: hair dryer, ping-pong ball, curved paper. Procedure: turn on hair dryer, place ball in airflow so it hovers, move curved paper near jet — the ball follows the curved airflow, demonstrating Coandă.
A 4 kg sign hangs at the end of a 0.5 m horizontal rod attached to a wall by a hinge. What is the hinge's vertical force component? (Use g=9.8 m/s2.)
Weight = 4kg x 9.8 = 39.2 N downward. Hinge vertical force must balance weight, so the vertical force by the hinge is 39.2 N upward.
You want to test whether a pendulum's period changes with string length. Describe one simple data-only method to decide if length affects period.
Measure the period (time for several swings) for at least three different lengths; repeat each length 3 times and record averages. Make a scatter plot with length on the x-axis and average period on the y-axis. If the points show a clear upward trend (period increases as length increases), conclude length affects period; if points are flat, conclude no effect.