Rotations part 1

Question 1

If an object is in equilibrium the net torque is equal to what?

Answer 1

The net torque is equal to zero in equilibrium

Question 2

What are the two conditions for an object to be in static equilibrium?

Answer 2

sum of external forces =0
sum of external torques =0

Question 3

fulcrum

Answer 3

balancing point

Question 4

Torque

Answer 4

rotational force which causes a change in rotational motion

Question 5

Torque equation

Answer 5

T = F x r

Question 6

force must be applied _____ to the radius (lever arm) in order to create rotation

Answer 6

perpendicular

Question 7

Max rotation

Answer 7

r and F perfectly perpendicular

Question 8

no rotation when

Answer 8

force is applied straight towards the object

Question 9

When force is not perpendicular?

Answer 9

T = r Fsinx
T = rFcosx

Question 10

solve any torque problem with

Answer 10

the sum of external forces equal 0

Question 11

angular kinematics is measured in?

Answer 11

Radians

Question 12

angular speed

Answer 12

how fast the angle changes theta/ t

Question 13

positive angle =
negative angle=

Answer 13

counter clockwise
clockwise

Question 14

convert linear velocity to angular velocity

Answer 14

v= w x r
w = v/r

Question 15

convert linear acceleration to angular acceleration

Answer 15

a = A x r
A = a/r

Question 16

revolutions is…

Answer 16

theta
angular displacement/ 2pi

Question 17

frequency to angular velocity

Answer 17

2pi(f) rev/sec
2pi(f)/60 rev/min

Question 18

moment of inertia

Answer 18

an objects resistance to rotational acceleration

Question 19

rotational inertia is dependent on

Answer 19

1. the mass of an object
2. the distribution of the mass about the chosen axis of rotation

Question 20

What objects are easier to accelerate?

Answer 20

objects with a smaller moment of inertia are easier to accelerate

Question 21

rotational motion

Answer 21

T = I x A

Question 22

for T = I x A
what happens if F doubles?
I doubles

Answer 22

F doubles, A doubles
I doubles, A(1/2)

Question 23

sum of forces in x to find Rx

Answer 23

Rx + Fcosx

Question 24

sum of forces in y to find Ry

Answer 24

Ry- F - F + Fsinx

Question 25

how to find R (force of an angle without known angle)

Answer 25

Sq/rt (Rx)^2+(Ry)^2