matter and energy

Question 1

who was the first to suggest the concept of gravity changing many of popular beliefs of his time.?

Answer 1

Galileo Galilei

Question 2

A positive velocity shows that a body is moving…

Answer 2

upwards

Question 3

A negative velocity shows that a body is moving…

Answer 3

downwards

Question 4

The value of gravity has to be ….. all the time.

Answer 4

negative

Question 5

free fall

Answer 5

we assume that the initial velocity of the object is zero. Also, the final velocity and position are going to increase negatively because our initial position is zero. Gravity must be negative always.

Question 6

parabolic motion

Answer 6

analyze the behavior of the projectile along its trajectory,

Question 7

angular displacement

Answer 7

shows us its amount of rotation

Question 8

angular velocity

Answer 8

the angular displacement per unit of time

Question 9

If the angular velocity is in revolutions per second (rev/s) we call it

Answer 9

angular frequency

Question 10

tangential velocity

Answer 10

this is the linear velocity that a body has when it is rotating at a certain angular velocity and which we also know the distance to the rotational axis, the radius:

Question 11

physical quantity that measures the intensity of the interaction between two or more objects.

Answer 11

a vector

Question 12

two type of forces

Answer 12

contact force and no-contact force

Question 13

what is mass

Answer 13

the amount of matter that possess a body or as the physical scalar quantity that measures the resistance of an object for either acquiring motion, or to amend its motion condition

Question 14

three newton laws

Answer 14

first/inertia law
second/law of motion: f-ma
third/action-reaction law

Question 15

Weight:

Answer 15

Is a distance force due to the interaction of a mass with the gravitational field produced by the earth.

Question 16

normal force

Answer 16

Is a contact force due to contact between an object with a plane or a surface and this force has a direction that is perpendicular to the contact surface.

Question 17

tension in a rope force

Answer 17

A force manifested in every point of a rope due to the application of two equal forces on each end of the rope.

Question 18

free-body diagram

Answer 18

is a diagram showing the forces acting on an object, where the direction of the forces depends on the characteristics of the type of forces applied.

Question 19

two type of friction

Answer 19

Static friction: Without relative motion.
Kinetic friction: With relative motion.

Question 20

first equilibrium condition

Answer 20

is that there is no resultant force. That means that the sum of all acting forces is equal to zero