Fear
what is the name for a phenomena that always causes a change in motion; often described simply as a push or a pull
a force
The SI unit of force is
Newton
When the vector sum of all forces on a system is zero, the system is said to be in _____________________.
mechanical equilibrium
(balance, I'll take, but the first thing is better)
Which instrument did we use to measure forces during our lab? What is it called?
a spring scale
give an example of a system in which the forces are unbalanced
any system that is accelerating, or changing direction
If an object changes velocity, what can be assumed about the object?
there is some force acting on the object
What units make up a Newton?
kg*m/s^2
If the external force acting on an object is doubled, then its acceleration is
doubled
What did Galileo hypothesize about the rate objects of differing masses fall that was later proved during Apollo 15
In the absence of air resistance, all objects fall at the same rate
What is the mass of an elephant with a weight of 29430 Newtons?
3000 kg
What is net force?
the sum of all external forces acting on an object
State Newton's third law in your own words
For every force acting on a system, there is an opposing force of equal magnitude acting on the opposing system in the opposite direction.
Forces always occur in pairs
What is Newton's 2nd law
∑F = ma
Note, the ∑F refers to the resultant force on the system
When you kick a soccer ball, it will fly through the air, but when you kick a bowling ball with the same force, it will only move a little bit, and you will break your foot. Which of Newton's laws best describes the lack of motion of the bowling ball?
1st. the bowling ball's inertia is high, so it doesn't like a change in motion.
1st law states that an object at rest will remain at rest, or an object at motion will remain in motion in a straight line with a constant velocity until acted on by an unbalanced force.
compute the standard weight of a 35 kg mass
343.35 N
List the 4 fundamental forces
gravity, electromagnetic (light, magnetism and electricity) force, strong nuclear force, weak nuclear force
Newton's laws of motion are the basis for the area of physics that describes the sources of movement. What is this area of physics called?
Dynamics
Aristotle's ideas were undisputed for over 2000 years due to what Latin two-word reason>
Ipse Dixit
If you are driving at a constant speed of 15 m/s and you see a middle schooler fortnite dancing in the middle of the street. You reluctantly slam on the brakes and stop moving over the course of 1.7 seconds from hitting the brakes. What is your acceleration?
-8.8 m/s2
You are keeping a car from rolling down a hill. You push with a force of 600 N at an upward angle of 20°. What is the magnitude and direction of the equilibrant force that the car is pushing on you.
600 N at a downward slope of 200° or -20° in the opposite direction
A 1500.0 N force is exerted on a 200.0 kg crate to move it across the floor. If the coefficient of friction is .250, what is the crate's acceleration?
5.05 m/s^2
List at least 4 external forces and briefly describe them or demonstrate them
Applied, friction, tension, Normal, Ari resistance, Gravitational (weight)
There are six books in a stack, and each book weighs 5 N. The coefficient of friction between the books is 0.2. With what horizontal force must one push to start sliding the top five books off the bottom one?
F > 5N
A force of 35 N can move an object at an acceleration of 10 m/s2, what is the weight in Newtons of the object in question
it's weight is 34.3 N
Its mass is 35/10 = 3.5 kg, so 3.5 x 9.81 is 34.335 N
A 20.0 kg block is accelerating down a ramp at 5.00 m/s^2. If the ramp is at an angle of 60 degrees, what is the coefficient of kinetic friction?
0.71