Last-minute AP Physics 1 Unit 2 Test Flashcards

Ugh I hate physics since I fall asleep in that class

μ (coefficient of friction)

μ = friction force ÷ normal force. Unitless number that tells how “grippy” two surfaces are.

Why can’t Linda lift a 1200 N object by pulling a pulley? She is 800 N but can lift 1600 N.

If she is pulling, there is no normal force to back her up like it would when she’s lifting something. She weighs less than the object so she will just get pulled up the pulley.

Horizontal net force when pushing against friction (flat ground)

Fnetx = Fapplied − f = ma → a = (F_applied − f) / m

How to get the acceleration of the cart along the table?

F_net = ma = F_gm - T → T = F_gm - ma

Two angled strings. How to solve?

Two strings have the same y tension (same as F_g of the hanging object). Solve for the x tension using the angle and the y tension. Then, use the Pythagorean Theorem to solve for the actual tensions.

Elevator problems. How to solve for apparent weight?

First solve for the acceleration. Then, do F_g = ma using the solved acceleration. Constant speed means the weight will be normal since there is no acceleration.

Constant speed up an incline (net force parallel = 0)

F_applied − mg sin θ − f = 0 → friction = F_applied − mg sin θ

Spinning object attached to string force formula

F_c =