Newton's Laws of Motion

Question 1

In simple terms, what is acceleration and velocity?

Answer 1

position
velocity
quickly

Question 2

if velocity is increasing, what do we call it??
if velocity is decreasing what do we call it?

Question 3

Give 2 differences between speed and velocity?

Answer 3

1. direction
2. displacement

Question 4

is average speed necessarily equal to magnitude of average velocity? give a numerical example

Question 5

A runner runs half the remaining distance to the fi nish line every ten seconds. She runs in a straight line
and does not ever reverse her direction. Does her acceleration have a constant magnitude?

Answer 5

deceleration

Question 6

What is Newton’s first law of motion? Give an example

Answer 6

An object continues in a state of rest or in a state of motion at a constant velocity (constant
speed in a constant direction), unless compelled to change that state by a net force.
Ice Hockey - Remove forces like friction and air resistance.

Question 7

What is inertia?
example, SI unit

Answer 7

The tendency of the object to maintain its state of rest of or of uniform motion in a straight line is called inertia.
Schoolbags
Kg

Question 8

what is newton’s second law of motion?

Answer 8

The acceleration of the object is directly proportional to the net force acting on it, and is inversely proportional to its mass. The direction of acceleration is in the direction of net force acting on the object.

Question 9

Give example to show that acceleration is directly proportional to force and inversely proportional to mass

Answer 9

1.Pushing a cart
2. pushing a empty cart and cart full of fruits with same net force.

Question 10

Whats the SI unit of Force

Answer 10

Kg m/s^2

Question 11

what does Newtons third law of motion say? examples

Answer 11

Whenever one object exerts a force on second object, the second exerts a equal force in opposite direction on the first.
1) hammer and nail
speed of hammer reduced to zero.
2) skater
3) Rocket expulsion.
4) walking (try walking on ice)
5) a flying bird.

Question 12

What exerts a force on the car??

Answer 12

ground not engine

Question 13

Inanimate can exert force because of __________
example to understand?

Answer 13

elasticity

Question 14

Define work

Answer 14

The product of magnitude of displacement times the component of the force parallel to the displacement.
W=FDcos teta

Question 15

can W=0 if the force is acting on the object.
eg

Answer 15

If there is no displacement, then w=0
The person doing no work on the bag of groceries since Fp is perpendicular to displacement D

Question 16

a box dragged across a floor by Force Fp which makes and angle teta along the horizontal. If the magnitude is held constant and and angle teta increased work done by Fp
1. Remains the same
2. increases
3.decreases
4. increases then decreases

Answer 16

decreases
becoz cos 90 = 0

Question 17

What is energy??

Answer 17

ability to do work

Question 18

Kinetic energy

Answer 18

1) A moving object can do work on another object it strikes.
2)energy of motion
3)An object in motion has ability to do work and thus can be said to have energy.
4) A moving object exerts a force on second object which undergoes a displacement.

Question 19

Kinetic energy Examples

Answer 19

1)A flying cannon ball does work on the brick wall it knocks down.
2)A moving object does work on nail it drives into the wood.

Question 20

Whats the work energy principle?

Answer 20

The net work done on the object is equal to change in objects kinetic energy.