Exam 3 Linear Monentum and Torque

Energy is conserved in an isolated system. T or F

Energy is conserved in an isolated system. T or F

T

What is the variable of linear momentum?

p

What is the mathematical definition of momentum?

the product of mass and velocity (p=mv)

Is momentum a scalar or vector quantity?

vector

What is the form of Newton's 2nd law written in terms of momentum?

Fnet= delta p/delta t or Fnet x Delta t = delta p

A change in momentum always requires a net force. T or F

T

The impulse that acts

equals the change in momentum that occurs

What is Pnet?

Pnet= m1v1 + m2v2+m3v3…

Is impulse a vector or scalar quantity?

vector

What is the mathematical definition of impulse?

change in momentum of an object when a force acts on it for a period of time

What is the relation between and the direction of change of momentum and the direction of impulse?

The change in momentum of an object is equal to the impulse applied to it.

What type of graph can be related to impulse as the area between the curve and the horizontal axis?

force vs time

What 3 characteristics are used to define torque?

strength, direction and position

What is Torque?

the effectiveness of a force in producing changes in rotational motion.

What is the equation for torque?

r: distance from pivot to point where force is applied

F: magnitue of applied force

0I: angle between the radial line and the direction of the force.

What is the radial line?

an imaginary line that passes through the pivot point and the point where force is applied

A  positive (+) torque

rotates the object in a counter-clockwise direction.

A negative (−) torque

rotates the object in a clockwise direction is designated as.

Lever Arm Torque:

In order for an object to be in static equilibrium, the object…

is in transnational and rotational rest, and the net force and net torque must be zero

What conserves internal kinetic energy?

elastic collisions

What is a collision in which the objects stick together is?

perfectly inelastic collision

In circular motion, linear acceleration is _______ to the circle at the point of interest.

tangent

Linear or tangential acceleration refers to changes in the magnitude of _______ but not its ________.

velocity; direction