Motion, Energy And Gravity. Ch 4

Question 0

Spaceship in space is an example of what

Answer 0

Newtons 1st law. An object moves at constant velocity unless a net force acts to change its speed or direction

Question 1

Newtons 1st law

Answer 1

An object moves at constant velocity if there is no net force acting upon it. Objects at rest (velocity=0) tend to stay at rest

Question 2

Acceleration must be in the ? Direction as the force

Answer 2

Same

Question 3

Force equals mass times acceleration

Answer 3

Newton’s 2nd law. Or force equals rate of change in momentum

Question 4

Baseball pitcher, car going around a curve, planet going around Sun

Answer 4

Newton’s 2nd law

Question 5

For any force there is always an equal and opposite reaction force

Answer 5

Newton’s 3rd law.

Objects always attract each other through gravity

Question 6

A rocket engine generates a force that drives hot gas out the back which creates an equal and opposite force that propels the rocket forward.

Answer 6

Newtons 3rd law

Question 7

The .? Of the car tell Jim how far it will go in a certain amount of time

Answer 7

Speed

Question 8

100 km/h going due north

Answer 8

Velocity. Speed and direction.

Question 9

If velocity is changing in anyway whether in speed or direction or both

Answer 9

Acceleration

Question 10

Mass times velocity

Answer 10

Momentum

Question 11

The only way to change objects momentum is to apply

Answer 11

A force to it

Question 12

The amount of matter in your body

Answer 12

Mass

Question 13

Depends on both your mass and the gravity acting on your mass

Answer 13

Weight

Question 14

Astronauts are weightless the entire time they orbit Earth because

Answer 14

They are in a constant state of freefall

Question 15

an objects momentum cannot change unless the object transfers momentum to or from other objects

Answer 15

Conservation of momentum.

Question 16

planets rotations and orbit ? change unless the planet transfers angular momentum to another object. Our planets do NOT exchange substantial angular momentum with each other or anything else

Answer 16

cConservation of angular momentum. CAN NOT

Question 17

Energy is always

Answer 17

Conserved.

Question 18

Three types of energy

Answer 18

kinetic, radiative, potential

Question 19

Kinetic energy (motion)

Answer 19

falling rocks, orbiting planets, molecules in air

Thermal depends on temp, density of particles,

Question 20

Radiative energy

Answer 20

all light carries energy. Light can cause changes in matter.

Question 21

Potential energy

Answer 21

stored energy. can be converted to other two types of energy.

Joule. the standard unit of energy in science
A. Gravitational potential energy
B. Mass energy mass itself is a form of potential energy (Einstein)

Question 22

three types of orbital paths

Answer 22

Ellipses
Bound orbits over and over again
unbound orbits paths that bring object close to another object just once.

Question 23

Newton showed 3 kinds of orbits

Answer 23

Ellipses
parablolas
hyperbolas

Think of cone sliced up. extends Keplers third law.

Question 24

Universal law of gravitation

Answer 24

every object attracts every other with a gravitational force that is proportional to the product of the ojects masses and declines with the quare of the distance between their centers.

Question 25

if an object can gain energy from transfer with other object it can achieve

Answer 25

escape velocity.

Question 26

sum of an objects kinetic and gravitations potential energy

Answer 26

Orbital energy.

Question 27

tidal force

Answer 27

moons gravity. stretches earth along the Earth-moon line.

Question 28

Earths rotation carries us through the two bulges each day.
2 high tides
2 low tides

leads to ?

Answer 28

Tidal friction . slowing earths rotation and explains the Synchronous rotation of the moon

Question 29

Do all objects fall at the same rate

Answer 29

YES.

acceleration of gravity is independent of mass