Type: Double
Date: __________
Objective: Equilibrium Applications of Newton’s Laws of
Motion II
Equilibrium Applications of Newton’s Laws of
Motion III
Homework: Assignment (1-12)
Do PROB #’s (53, 59) Ch. 4 +
Do AP 1980 #1 (AP-handout)
AP Physics “B”
Mr. Mirro
Date: ________
Equilibrium, Statics and Newton’s Laws II
Ex 1: A 0.60 kg kite is being flown at the end of a string. The string is straight and makes an angle of
55.0° above the horizontal. The kite is stationary and the tension in the string is 35.0 N. Determine
the magnitude and direction of the force that the wind exerts on the kite. Specify the angle relative
to the horizontal. [Cutnell4EP#63]
Ex 2: An automobile engine has a weight W, whose magnitude is W = 3150 N. This engine is being
positioned above an engine compartment, as shown. To position the engine, a worker is using a
rope. Find the tension T1 in the supporting cable and the tension T2 in the positioning rope.
[Cutnell4.12]
AP Physics “B”
Mr. Mirro
Date: ________
Equilibrium, Statics and Newton’s Laws III
Ex 1: The figure shows a traction device used with a foot injury. The weight of the 2.2 kg mass creates a
tension in the rope that passes around the pulleys. Therefore, tension forces T1 and T2 are applied
to the pulley on the foot. The foot pulley is kept in equilibrium, because the foot also applies a
force F to it. This force arises in reaction to the pulling effect of the forces T1 and T2. Ignoring
the weight of the foot, find the magnitude of F. [Cutnell4.11]
Space diagram for the foot pulley
Ex 2: Finding her car stuck in the mud, a bright graduate of a good physics course ties a strong rope to
the back bumper of the car, and the other end to a tree as shown. She pushes at the midpoint of the
rope with her maximum effort, which she estimates to be a force Fp ≈ 300 N. The car just begins to
budge with the rope at an angle which she estimates to be about 5°. With what force is the rope
pulling on the car ? Neglect the mass of the rope. [Giancoli4.13]
Fp
Tree
T1
T2
θ
θ