Physics Chapter 2

Velocity

30 Mph North is an example of

Speed

30 Mph is an example of

400 N (When you're on the scale you're in mechanical equilibrium, this means your weight is distributed evenly with the normal force that is supporting you on the scales. This is in accordance with Newton's 3rd law. So even if you lean your weight onto one scale more than the other, both scale must add up to your entire weight, since normal force is canceling out all the forces you're putting on the scales to zero.)

A man weighing 800 N stands at rest on two bathroom scales so that his weight is distributed evenly over both scales. The reading on each scale is? *Give explanation*

about 30 m/s (This is because according to newton's 1st law an object in motion tends to stay in motion due to its inertia. In the case of the box, the box is moving at a constant velocity of 30 m/s, and the boxes speed continues at this rate, even when it falls from the truck)

A package falls off a truck that is moving at 30 m/s. Neglecting air resistance, the horizontal speed of the package just before it hits the ground is *Give explanation*

Scalar

A physical quantity that has magnitude only.

vector

A quantity that has magnitude and direction

the milk carton has inertia

A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that *Give explanation*

exactly below the midpoint of the ceiling. (This is because according to newton's 1st law an object in motion tends to stay in motion due to its inertia. In the case of the rock, the rock is moving at a constant velocity with the truck, and the rock's speed continues at this rate, even when it falls in the truck, allowing the rock to land right below where it was dropped)

A truck is moving at constant velocity. Inside the storage compartment, a rock is dropped from the midpoint of the ceiling and strikes the floor below. The rock hits the floor *Give explanation*

Velocity

A vector, shows how fast and in what direction

10 m/s (and it keeps multiplying by 10 for as long as the object is falling)

After the first second an object starts to fall from a resting state, what is the speed of it's fall after the first second and every second after.

Instantaneous speed

Average speed for a particular moment

Acceleration

Change in velocity/Time

Speed =

Distance ------------ Time

(change in velocity)/(time)

Formula for Acceleration is

Average speed= total distance/ total time

Formula for Average speed

S=D/T

Formula for Speed

g=2d/t(squared)

Formula used to measure g

using a free fall apparatus

How could we measure gravity (g)

Speed

How fast something moves; the distance traveled per unit of time.

Acceleration

How quickly motion changes

Changing velocity

If either the speed or the direction changes (or both change), then the ______ changes.

continue moving at the same velocity.

If no external forces are acting on a moving object, it will

inertia (This is because according to newton's 1st law an object in motion tends to stay in motion due to its inertia, and even when the automobile's engine stops inertia allows it to stay in motion until something stops it like the friction of the road)

If your automobile runs out of fuel while you are driving, the engine stops but you do not come to an abrupt stop. The concept that most explains why is *Give explanation*

Newton's First Law of Motion

Law of Intertia - An object in motion will stay in motion, and an object at rest will stay at rest, unless acted upon by force

Linear motion

Motion along a straight-line path.

Constant velocity

Motion in a straight line at a constant speed

Free Fall

Motion under the influence of gravity only.

Every object continues in a state of rest or of uniform speed in a straight line unless acted on by a nonzero net force

Newtons 1st law

Instantaneous speed

Speed at any instant.

scalar

Speed is a ______

Constant speed

Steady speed.

According to newton's first law an object under the influence of only one force cannot be in mechanical equilibrium In this case two forces act on the object, The pushing force, and according to newton's 3rd law, the equal and opposite friction force pushing back. Putting the object into mechanical equilibrium

The force of friction on a sliding object is 10 N. The applied force needed to maintain a constant velocity is *Give explanation*

Acceleration

The rate at which velocity changes with time; the change in velocity may be in magnitude, or direction, or both.

Velocity

The speed of an object and a specification of its direction of motion.

Instantaneous speed

This is what your car speed-o-meter reads

vector

Velocity is a_____

means when a vector is given. It gives you the direction of the force, and the strength of the forch.

What does it mean that vectors have magnitude and direction

An object is in a mechanical equilibrium when it has a has a net force of zero. This means that all forces acting on the object sum up to zero. This can be applied to an object at rest such as a calculator that's sitting on your desk, or an object in constant motion such as an asteroid with a straight trajectory.

What does it mean to say something is in mechanical equilibrium?

no longer accelerates (because it enters into mechanical equilibrium)

When a rocket ship accelerating in outer space runs out of fuel, it

Mechanical equilibrium not in motion

When an object is at complete rest this is an example of?

Mechanical equilibrium content motion

When an object is moving at a constant speed and velocity this is an example of?

add up to equal your weight (When you're on the scale you're in mechanical equilibrium, this means your weight is distributed evenly with the normal force that is supporting you on the scales. This is in accordance with Newton's 3rd law. So even if you lean your weight onto one scale more than the other, both scale must add up to your entire weight, since normal force is canceling out all the forces you're putting on the scales to zero.)

When you stand at rest on a pair of bathroom scales, the readings on the scales will always When you stand at rest on a pair of bathroom scales, the readings on the scales will always add up to equal your weight. each equal your weight. each be half your weight. *Give explanation*

experiment

Whereas Aristotle relied on logic in explaining nature

follow a straight-line path (The velocity is still there, but it no longer has the string to change its trajectory.)

Whirl a rock at the end of a string and it follows a circular path. If the string breaks, the tendency of the rock is to *Give explanation*

This is because a force quantifies magnitude and direction.

Why do we say that force is a vector quantity?

No because inertia is a property of matter to behave this way, NOT a force

Your friend says inertia is a force that keeps things in their place at rest or in motion. do you agree?

Acceleration (along a straight line) =

change in speed --------------------- time interval

Acceleration =

change of velocity ----------------------- time interval

Distance fallen in free fall, from rest;

d = ½ gt²

5 m/s

during the first second an object starts to fall from a resting state, what is the speed of it'd fall for the first second

d=(1/2)(g * t)squared

formula to calculate the distance traveled, of a falling object.

Mechanical equilibrium

has a net force of zero

Motion

is relative.

Sum of all forces acting on an object

net force

Relative Motion

observers measure motion relative to their own

Speed

scalar, shows how fast

Relative Motion

the change in position of one object compared to the position of another

Average speed =

total distance covered ---------------------------- time interval

Velocity acquired in free fall, from rest;

v = gt