30 AP Physics 1 Exit Tickets by Unit

Grade a Stack in Five Minutes

A two-minute exit ticket only pays off if grading it does not eat the two minutes back ten times over. Work from a set of one-line answer keys, not full solutions, and grade in three passes instead of one.

First pass, one minute: flip through the whole stack once, sorting into three piles by eye alone. Pile one is "clearly has it," where the paper states the one required line in some form. Pile two is "clearly does not," where the paper is blank, off-topic, or contradicts the required line outright. Pile three is "read closer," anything with the right numbers but a shaky reason, or a reason without the number.

Second pass, three minutes: work only pile three. That pile is almost always the smallest of the three and the only one that needs real reading, so this is where your time actually goes. Everything you learn there, common wrong number, common missing reason, common mixed-up formula, becomes tomorrow's warm-up.

Third pass, one minute: count each pile. If pile two is more than a third of the class, that topic needs full reteaching before you move on, not just a follow-up problem for the few who missed it. If pile three dominates, the ticket tested a genuine edge case and a short clarifying example next class covers it. Piles one and two need no comments at all; save your written feedback for pile three, where a single sentence pointing at the missing piece does more than a grade.

This only works because each ticket below asks for one line, not a full derivation. Reword any ticket you like, but keep the one-line answer key intact, since a key with two or three required pieces turns the fast sort back into a slow read.

Unit 1: Kinematics (4 tickets)

1. A ball is thrown straight up and caught again at the same height it left your hand. Describe its acceleration at the very top of the flight, where its velocity is zero. Answer must include: Acceleration stays 9.8 m/s^2 downward at every point of the flight, including the top, even though velocity is momentarily zero there.
2. A position-time graph is a straight line with a negative slope. What does that say about the object's velocity? Answer must include: Velocity is constant, and its sign matches the slope: constant speed moving in the negative direction.
3. A velocity-time graph runs in a straight line from 10 m/s at t = 0 to 0 m/s at t = 4 s. Find the displacement over those 4 seconds. Answer must include: 20 m, from the area under the line (1/2 x 10 m/s x 4 s, or an average velocity of 5 m/s over 4 s).
4. A projectile is launched at an angle above the horizontal. Compare its horizontal and vertical acceleration at the peak of its path. Try it on the [Projectile Launcher](/interactives/projectile-launcher) before answering. Answer must include: Horizontal acceleration is 0 at every point; vertical acceleration is 9.8 m/s^2 downward at the peak too, unchanged from the rest of the flight.

Unit 2: Force and Translational Dynamics (5 tickets)

1. A block sits on a frictionless incline. Name the only two forces that belong on its free-body diagram. Sketch it on the [Free-Body Diagram Builder](/interactives/free-body-diagram-builder) or check it against the [Inclined Plane Simulator](/interactives/inclined-plane-simulator). Answer must include: Gravity (weight, straight down) and the normal force (perpendicular to the incline surface). No friction, since the incline is frictionless.
2. Two carts of different mass are connected by a string and pulled across a frictionless table by a force F applied to the front cart. Is the string tension equal to F? Answer must include: No, tension is less than F, because the string only has to accelerate the back cart, so T = m_back x a with a = F / (m_front + m_back).
3. A 2 kg block on a table feels a 10 N applied force and a 4 N friction force opposing its motion. Find its acceleration. Answer must include: 3 m/s^2, from Newton's second law: net force = 10 N minus 4 N = 6 N, and a = F_net / m = 6 N / 2 kg.
4. An elevator accelerates upward. Explain why the normal force the floor exerts on a passenger is greater than the passenger's weight. Answer must include: The normal force must exceed weight to supply the extra upward net force: N minus mg equals ma, so N equals mg plus ma, which is greater than mg.
5. A spring stretches 0.2 m when a 4 N weight hangs from it. Find the spring constant. Answer must include: 20 N/m, from Hooke's law: k = F / x = 4 N / 0.2 m.

Unit 3: Work, Energy, and Power (4 tickets)

1. A 2 kg cart starts from rest and rolls 1.5 m down a frictionless ramp. Find its speed at the bottom using energy conservation. Answer must include: About 5.4 m/s, from mgh = 1/2 m v^2, which gives v = the square root of (2 x 9.8 x 1.5).
2. A 20 N force pushes a box 3 m in the same direction as the push. How much work is done on the box? Answer must include: 60 J, from W = F x d = 20 N x 3 m.
3. A roller coaster car has 500 J of kinetic energy and 300 J of gravitational potential energy at one point on the track. With friction and air resistance ignored, what is its total mechanical energy at every other point on the track? Answer must include: 800 J at every point, since mechanical energy is conserved once friction and air resistance are ignored.
4. A motor does 600 J of work on a load in 4 s. Find its power output. Answer must include: 150 W, from P = W / t = 600 J / 4 s.

Unit 4: Linear Momentum (3 tickets)

1. A 0.5 kg ball moving at 6 m/s hits a wall and bounces straight back at 6 m/s. Find the magnitude of the impulse the wall delivers to the ball. Answer must include: 6 kg m/s, from the change in momentum: 0.5 kg x (6 m/s minus negative 6 m/s) equals 6 kg m/s, direction reversed.
2. Two carts of equal mass collide and stick together. Cart A moves at 4 m/s and cart B starts at rest. Find their common velocity after the collision. Check your reasoning on the [Collision Lab](/interactives/collision-lab). Answer must include: 2 m/s, from conservation of momentum in a perfectly inelastic collision: (m x 4 + m x 0) / (2m) = 2 m/s.
3. A 1000 kg car traveling at 20 m/s hits a wall and comes to rest in 0.1 s. Find the average force the wall exerts on the car. Answer must include: 2.0 x 10^5 N, from F = change in momentum / time = (1000 kg x 20 m/s) / 0.1 s.

Unit 5: Torque and Rotational Dynamics (4 tickets)

1. A 10 N force is applied perpendicular to a wrench, 0.3 m from the bolt. Find the torque on the bolt. Answer must include: 3 N m, from torque = r x F = 0.3 m x 10 N, applied perpendicular to the wrench.
2. A seesaw balances with a 40 kg child sitting 1.5 m from the pivot. How far from the pivot, on the other side, must a 30 kg child sit to balance it? Answer must include: 2.0 m, from setting the two torques equal: 40 kg x 1.5 m = 30 kg x d.
3. Two objects have equal mass but different rotational inertia about the same axis. Under the same applied torque, which one is harder to spin up? Answer must include: The one with the larger rotational inertia, since angular acceleration equals torque divided by rotational inertia, so a bigger I gives a smaller alpha for the same torque.
4. Name the two quantities you need to compute a rotating platform's angular acceleration from torque = I x alpha. Answer must include: The net torque acting on the platform and its rotational inertia (moment of inertia) about the spin axis.

Unit 6: Energy and Momentum of Rotating Systems (3 tickets)

1. A solid disk and a hoop, matched in mass and radius, are released from rest at the top of the same ramp and both roll without slipping. Which reaches the bottom first? Answer must include: The solid disk, because its smaller rotational inertia sends a larger share of the released energy into translational kinetic energy.
2. A figure skater spinning with her arms out pulls her arms in close to her body. What happens to her angular velocity, and why? Answer must include: It increases, because angular momentum (L = I x omega) is conserved and her rotational inertia I drops as her arms come in.
3. A ball rolls without slipping down a ramp. Name the two forms of kinetic energy it has at the bottom. Answer must include: Translational kinetic energy (1/2 m v^2) and rotational kinetic energy (1/2 I omega^2).

Unit 7: Oscillations (3 tickets)

1. A mass on a spring is pulled back from equilibrium and released from rest. At what point in its motion is its speed at a maximum? Answer must include: At the equilibrium position, where displacement is zero, because that is where all of the system's energy is kinetic.
2. The mass on a spring is doubled while the spring constant k stays the same. What happens to the period of oscillation? Answer must include: The period increases by a factor equal to the square root of 2, since T = 2 pi times the square root of (m / k).
3. A simple pendulum has a period of 2 s on Earth. Would its period be longer, shorter, or the same on the Moon, where gravity is weaker? Answer must include: Longer, since T = 2 pi times the square root of (L / g), and a smaller g in the denominator makes T bigger.

Unit 8: Fluids (4 tickets)

1. A block floats in water with 70% of its volume submerged. Find the block's density. Answer must include: 700 kg/m^3, since the submerged fraction of a floating object equals its density divided by the fluid's density: 0.70 x 1000 kg/m^3.
2. Water flowing through a wide pipe enters a section where the pipe narrows. Does the water's speed increase, decrease, or stay the same? Answer must include: It increases, from the continuity equation A1 v1 = A2 v2: a smaller cross-sectional area requires a higher speed to carry the same flow.
3. Along a horizontal pipe, where the fluid speeds up, what happens to the pressure there? Answer must include: The pressure decreases, from Bernoulli's equation: at the same height, a faster-moving fluid has lower pressure.
4. A block of density 2700 kg/m^3 is fully submerged in water (density 1000 kg/m^3) and released. Is the buoyant force on it larger, smaller, or equal to its weight? Answer must include: Smaller, since the block's density is greater than the water's, so it sinks and the buoyant force is less than its weight.