2- force

Question 1

Inertia=

mass=

weight=

center of mass=

center of gravity=

Answer 1

the tendency of an object to remain in its present state of motion.

quantitative measure of an object’s inertia.

gravitational force an object experiences when near a much larger body such as earth.

consider an object as a single particle where all its mass is concentrated through the middle of the object.

the point in an object where the force of gravity can be applied to the entire mass.

Question 2

5 nature of forces:

Answer 2

1) strong nuclear force
2) weak nuclear force
* *3) gravitational force
4) electromagnetic force
5) contact**

Question 3

Newton’s 1st law:

2nd Law:

3rd Law:

Answer 3

law of inertia; if the object is in a state of rest or in state of motion it will remain in this state unless it is acted upon by a force.

F=ma

for every action is an equal and opposite reaction.

Question 4

Newton’s law of universal gravitation:

Answer 4

states that every mass in the universe exerts an attractive force on every other mass in the universe.

F=(G)(m1m2/r2)

Question 5

Normal force:

Answer 5

on an inclined plane the force for gravity always equal to mgsin(theta)

and for the normal force–> mgcos(theta)

Question 6

Circular motion

• centripetal acceleration:
• centripetal force:

Answer 6

• c.a.–> Ac= (v^2)/r
• c.f.–> Fc= (mv^2)/r

Question 7

Normal force:

Frictional force:

Answer 7

perpendicular to the contact surface.

always parallel to contact surface

Question 8

Static friction (fs):

kinetic friction (fk):

Answer 8

force opposing motion when 2 contiguous surfaces arent moving relative to each other.

force resisting motion once the 2 contiguous surfaces are sliding relative to each other.

Question 9

2 coefficients of friction:

and when an object is sliding–>

Answer 9

fs <_ (Us)(Fn)

Fk= (Uk)(Fn)

-when an object is sliding Us>Uk

Question 10

tension:

Answer 10

force acting through a flexible object with no mass, such as a string or rope.

Question 11

Hooke’s Law:

Answer 11

F= -k(delta x)

K= (mg)/(delta x)