Definitions
A push or a pull
Force
True or False? An object moving to the right must have a rightward force on it?
False
What is the acceleration of a book falling to the ground? Assume air resistance is negligible.
9.8 m/s2
An object has a mass of 55 kg on Earth. What is its mass on the moon?
55 kg
Draw a free body diagram for a bird sitting on a tree branch
Drawing must show Fg and FN
Force exerted perpendicular to a surface
Normal Force
The force required to keep a 5 kg object moving to the right at 2 m/s.
0 N
What is the acceleration of a 75 kg object pushed with a net force of 250 N?
3.3 m/s2
What is the mass of an object that has a weight of 275 N?
28.1 kg
The mass of a 453 N box
46.2 kg
Force exerted on an object by gravity
Weight
The net force required to accelerate a 12 kg object at 7 m/s2
84 N
For a constant force, F, what will happen to acceleration if mass is tripled?
The acceleration will be 1/3
What is the mass of a softball if a 45 N force causes it to accelerate at 250 m/s2?
0.18 kg
Draw a freebody diagram for a book being pushed to the right across a table with a constant velocity
Diagram shall include Fg, FN, FA, and FF
Tendency of objects to resist a change in motion
Inertia
A 0.06 kg tennis ball hits a 0.3kg racket with a force of 40 N. What is the force of the racket on the tennis ball? Include both magnitude and direction.
40 N in the opposite direction
What is the acceleration of a 65 kg object falling to the ground if it experiences 200 N of air resistance?
6.7 m/s2 towards the ground
A shopper applies 58 N to a cart sot that it accelerates at 3.5 m/s2. If the cart experiences 12N of friction, what is the cart's mass?
13 kg
Draw a freebody diagram for an 85kg person on an elevator accelerating downwards at 2.5 m/s2. Include the magnitude of each force.
FN = 620.5 N
FG = 833 N
Branch of physics that studies the causes of motion
Dynamics
The force of air resistance on a 65 kg skydiver accelerating towards the earth at 3.0 m/s2. Include both magnitude and direction.
442 N upwards
A 5.2 N force is applied to a 1.05 kg object to accelerate it rightwards. There is 3.29 N of friction. What is the object's acceleration?
1.82 m/s2
A house is lifted by a crane for relocation. The net force on the house is 2850N. The house moves from rest to 0.15m/s in 5s. What is the mass of the house?
95,000 kg
A person has a weight of 803.6N on Earth. What is their weight on the moon, where gravity is 1.6 m/s2?
131.2 N