physical science exam chapter 13

Question 1

First Law of Motion

Answer 1

An object in motion stays in motion and an object at rest stays at rest unless there is an unbalanced force.

Question 2

The first law is also known as?

Answer 2

Law of inertia

Question 3

Example of First Law of motion.

Answer 3

If a ball is rolling on the ground at a speed of 2m/s then. it will keep its state of motion till infinity if no unbalanced force acts upon it.

Question 4

Second Law of Motion

Answer 4

An object will always accelerate in the direction of that net force

Question 5

The second law is also known as

Answer 5

The law of acceleration

Question 6

Example of second Law of motion.

Answer 6

Pushing a shopping cart. The shopping cart with nothing in it will go faster because it has less mass while on the other hand a full shopping cart that weighs around 4 kg will weigh more and be harder to push because the mass is bigger.

Question 7

Weight

Answer 7

• Vector
• is affected by gravity (earth 9.8 m/s2)
• w=m(g)
• Weight is a downward force
• Weight is the gravitational force an object experiences because of its mass.
• SI unit: Newtons
• Weight influences the shape of living things

Question 8

Mass

Answer 8

Measure of the amount of matter in an object

• not affected by gravity
• scalar term
• SI unit: Kg
• mass does not change based on location

Question 9

Vector

Answer 9

a quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.

Question 10

Free fall

Answer 10

When there is no air pressure and Earth’s gravity is the only force acting on an object. Free fall acceleration is directed towards the center of the Earth. They all accelerate at the same rate regardless of the mass

Question 11

terminal velocity

Answer 11

when air resistance and weight are equal, the object stops accelerating and reaches its maximum velocity known as terminal velocity.

Question 12

projectile motion

Answer 12

the curved path that an object follows when thrown, launched, or otherwise projected near the surface of Earth

Question 13

projectile motion horizontal component

Answer 13

After you have thrown a ball, no horizontal forces are acting on the ball (if air resistance is ignored). So, the horizontal component of velocity of the ball is constant after the ball leaves your hand.

Question 14

Projectile motion vertical component

Answer 14

• When you throw a ball, gravity pulls it downward, which gives the ball vertical motion. In the absence of air resistance, gravity on Earth pulls objects that are in projectile motion downward with an acceleration of 9.8 m/s2, just as it pulls down all falling objects.

Question 15

inertia

Answer 15

The tendency of an object to resist a change

Question 16

Example of inertia

Answer 16

A soft ball has less mass, less inertia, than a bowling ball. It is easier to pitch and will change direction easily when hit with a bat. A bowling ball would be difficult to pitch and changing its direction would be difficult with a bat.

Question 17

2nd Law formula

Answer 17

F=ma

Question 18

3rd Law of motion

Answer 18

For every action there is an equal and opposite reaction

Question 19

This law is also known as

Answer 19

action reaction law

Question 20

example of this law of motion

Answer 20

Tires of a car push back against the road while the road pushes the tires forward.

Question 21

Law of Conservation of Mass

Answer 21

Matter is not created nor destroyed in any chemical or physical change

Question 22

Law of conservation of momentum

Answer 22

the total momentum of objects that collide is the same before and after the collision

Question 23

scalar

Answer 23

having only magnitude no direction.