Force and Newton's law study guide

Question 1

Force

Answer 1

A push or a pull

Question 2

what causes an acceleration

Answer 2

a net force

Question 3

difference of contact force and field force

Answer 3

Contact forces are exerted through contact and field forces are exerted without contact. Examples of contact force include pushing or pulling an object. Examples of a field force include gravitational forces and electromagnetic forces.

Question 4

Newton’s first law

Answer 4

“an object that is at rest will remain at rest and an object that is moving will continue to move in a straight line with constant speed if and only if the net force acting on that object is zero”

Question 5

inertia

Answer 5

the tendency of an object to resist changes in velocity; why objects with a greater mass tend to resist a change in motion more than those with a lesser mass

Question 6

force and acceleration have a ______ relationship

Answer 6

directly proportional

Question 7

The great the force, the greater the _______

Answer 7

acceleration

Question 8

what does it mean to have a direct and an inverse relationship in an equation?

Answer 8

Direct- y increases, x increases
Inverse- Y increases, x decreases; x increases, y decreases

Ex.) y = a/x, y is direct with a, it’s inverse with x

Question 9

Newton’s second law equation and units

Answer 9

Newton’s second law states that the acceleration of an object is directly related to the net force and inversely related to its mass.F = MA
Units: N

Question 10

Equation for weight and units

Answer 10

W=MG
kg x m/s^2 –> N

Question 11

6 common forces

Answer 11

friction, thrust, normal, weight, spring, tension

Question 12

What does it mean by net force? Example?

Answer 12

A net force is the vector sum of ALL forces acting on an object
EX: If one person pushes a box up with 40 N and someone pushes the same box forward with 30 N, the net force is 70 N

Question 13

equilibrium

Answer 13

When there is zero net force, meaning there is zero acceleration

Question 14

Newton’s third law

Answer 14

all forces come in pairs, For every action there is always an equal (magnitude) and opposite (direction) reaction

Question 15

Interaction Pair examples

Answer 15

student pulls a desk, desk pulls student; jevon sneed throws ball forward by exerting a force with hand on a ball, ball pushes back on hand

Question 16

Normal Force

Answer 16

the perpendicular contact force that a surface exerts on another surface

Question 17

Value of gravity on earth?

Answer 17

9.8 m/s^2

Question 18

Value of gravity on moon?

Answer 18

1.625 m/s^2

Question 19

Isaac Newton’s accomplishments

Answer 19

• President of Royal society and knighted in 1705
• Worked out the 3 laws of motion
• Born same year Galileo died
• wrote Principia Mathematica Philosophiae Naturalis
• At 46 was elected member of Parliament
• Discovered white light is composed of all colors of the rainbow
• Discovered Law of Universal gravitation extending to the moon and beyond

Question 20

Galileo Galilei’s accomplishments

Answer 20

• Remembered for his work in astronomy, math, & physics
• Showed that falling objects DO NOT have velocities proportional to their weight
• Found “mountains” on the moon
• Discovered 4 of Jupiter’s moons
• Saw imperfect spots on the sun
• “Eppur si muove”
• Discovered gravity (WITHOUT air resistance) acts the same on everything

Question 21

how does acceleration of an object change in relation to its mass?

Answer 21

Inversely proportional

Question 22

If the force acting on a cart doubles, what happens to the cart’s acceleration?

Answer 22

It doubles

Question 23

Label deck, wingwall, abutment, beams and pier on bridge

Answer 23

Deck: piece of the bridge you walk on
Abutment: Support at the ends of the bridge, usually made of concrete
Piers: vertical structure supports placed between abutments
Beams: Horizontal beam that is supported at each end by piers
Wingwall:the wing walls are adjacent to the abutments and act as retaining walls

Question 24

What bridge have many people tried to end their life on?

Answer 24

Golden Gate Bridge

Question 25

What’s the apex stone in the arch that locks all the stones into position?

Answer 25

Keystone

Question 26

What is the strongest geometric shape?

Answer 26

triangle

Question 27

What river does the London Bridge cross?

Answer 27

River Thames

Question 28

Beam Bridge

Answer 28

Piers support beams that support spans of concrete slabs, most common & least expensive

Question 29

Arch Bridge

Answer 29

Weight of bridge is transferred along the arch to piers & abutments

Question 30

Suspension Bridge

Answer 30

Have two towers that support main cables, used to span long distances

Question 31

Truss Bridge

Answer 31

A triangular framework used above or below to support bridge

Question 32

Cantilever Bridge

Answer 32

Beams extend from each end of the bridge

Question 33

Movable Bridge

Answer 33

Bridges are designed so that a portion of it can be moved to allow large water vessels to pass underneath

Question 34

Tacoma Narrows Bridge

Answer 34

Bridge that collapsed in a windstorm due to flutter, called Galloping Gertie, built in WA in the 1940s

Question 35

Brooklyn Bridge

Answer 35

Suspension bridge in NY, Engineer building it died in a bridge related accident, son finished the building, took 14 years and 30 lives, first truly modern bridge

Question 36

Golden Gate Bridge

Answer 36

A suspension bridge spanning the Golden gate, the opening of San Francisco bay into the Pacific Ocean

Question 37

How did the rocks on Racetrack Playa move?

Answer 37

They moved due to sheets of ice that were blown by light gusts of wind and and pushed against the rocks causing them to slide

Question 38

Why was gravity and high winds ruled out for finding out how the rocks moved?

Answer 38

Gravity was ruled out because the rocks moved up a slight slope, not downhill. High winds were ruled out because larger rocks would oftenly move further than smaller rocks.

Question 39

Interaction Pairs

Answer 39

a set of two forces that are in opposite directions, have equal magnitudes and act on different objects.