Physics 2 Question Quiz

Explain how average velocity is different from average speed in terms of how you
calculate each one.

average velocity : v = displacement/t
average speed : speed = distance/t

What is the difference between instantaneous velocity and instantaneous speed?

instantaneous velocity (vector - has direction); instantaneous speed is the absolute value of velocity (|v|), a scalar unit

Given a position vs. time graph, how do you find velocity?

slope

What can you get from the slope of the position vs. time-squared graph when the initial velocity is zero?

a or slope = 1/2a

Given a velocity vs. time graph, how do you find acceleration?

slope

Given a velocity vs. time graph, how do you find displacement?

total area = displacement or sum of the areas with the sign

Given a velocity vs. time graph, how do you find total distance traveled?

areas: distance or sum of the absolute value of the areas

Given acceleration vs. time graph, how do you find change in velocity?

sum of areas

Given a velocity vs. time graph, how do you find the time when the object passes through the initial position after t=0?

sum of areas = 0

How do you draw a line of best fit? You may draw an example

you draw a line b/w points (cant be above or below)

Describe the vertical velocity and acceleration in projectile motion as the object goes up and down

going up |vy| slows down/decreases ; vy = 0 (TOP) ; going down |Vy| increases speeds up ; ay = g ↓

Describe the horizontal velocity and acceleration in projectile motion.

vx = constant ; ax = 0

What is the difference between static friction and kinetic friction? Which coefficient is greater?

static friction (not moving yet); kinetic friction (moving); the coefficient of static is greater

What quantity gives you the measure of the translational (linear) inertia of an object?

mass

An object acted upon by a net force will always experience an An object acted upon by a net force will always experience an ___________, which
means it will either ___, ____, and/or ______

acceleration; speed up, slow down, or change direction

A force parallel to the velocity of an object makes it ________. A force perpendicular to the velocity of an object, makes it ________

speed up or slow down; turn (change direction)

Describe velocity, acceleration, and net force, when an object is in translational (linear) equilibrium.

velocity is constant, acceleration = 0, net force = 0

List the three fundamental forces in nature in terms of their magnitude from the weak to strong

gravitational force followed by electromagnetic and followed by nuclear

List the three fundamental forces in nature in terms of their range from short to long.

nuclear followed by electromagnetic followed by gravitational force

Two or more objects moving together (pulled by a rope of pushing each other) share the same__

|acceleration| or magnitude of acceleration

The normal force is always _______ to the surface.

perpendicular

The friction force always ____ the motion (or the intent of motion).and is proportional to the ___ force.

opposes, normal force

When the force applied is less than the maximum static force of friction, the
magnitude of the force of friction equals _______ and the acceleration equals ______

force applied ; zero

Given an object on an incline, list the components of its weight parallel and
perpendicular to the plane

Fg (parallel) = mgsin(theta) or Fgsin(theta) ; Fg (perpendicular) = mgcos(theta) or Fgcos(theta)

According to Hooke’s Law, the force needed to stretch (or compress) a spring depends on_______.

spring constant and distance stressed or compressed

What does the word centripetal mean? What quantities are centripetal in circular motion?

centripetal: towards the center ; acceleration and force

In UCM are centripetal acceleration, centripetal force, and tangential velocity
constant? Justify your answer

no - they change direction

In UCM, the centripetal force is proportional to______ and inversely proportional to
______.

mass and speed²; radius

The gravitational force between two objects is proportional to_____ and inversely proportional to _____.

mass, and mass2 ; (distance b/w them)²or r²

Mention what provides the centripetal force: for a simple pendulum - a car on a level surface - a car on a slanted road - a satellite - a conical pendulum - an object swirled horizontally using a rope.

simple pendulum: Ft - mgcos(theta) (force of tension)
car on a level surface: Force of friction b/w the tires and the road
car on a slanted road: Fn (normal force) sin(theta) ; satellite: Fg(force of gravity); conical pendulum: (Force of tension)sin(theta)
object swirled horizontally: force of tension

Given a Force vs. Distance graph, how do you find the work done by it?

area

Given a Net-Force vs. Distance graph, how do you find the change in Kinetic Energy?

area

What is a conservative force? Give an example.

work is independent of the path - Fg

What is a non-conservative force? Give an example.

Work depends on the path - Ff

Considering mechanical energy, when is a system open? When is a system closed?

open: Wexternal not equal 0
closed: no external work

Can a force perpendicular to the motion of an object do work on it? Justify your answer.

No, we use cos theta in the equation for work and the cosine of 90 degrees is equal to 0

The translational (linear) kinetic energy of an object is proportional to________

mv²

The gravitational potential energy of an object is proportional to________

mgh

The elastic potential energy of an object is proportional to________

kx²

Define power in your own words.

the rate at which work is done

In all collisions, _______ and ______ are conserved. Kinetic energy is conserved only in
_______ collisions

In all collisions, momentum and total energy are conserved.
Kinetic energy is conserved only in elastic collisions.

Considering momentum, when is a system open? When is it closed?

A system is open when external forces do act on it, changing its total momentum.
In an open system, momentum is not conserved.

What is the guarantee of a perfectly inelastic collision? What is the only guarantee of a perfectly elastic collision?

The two objects stick together after the collision.
Kinetic energy is conserved.

The linear momentum of a system is conserved when the _______ is zero. When that happens, ________ is also conserved.

when the net external force is zero.
When that happens, total momentum is also conserved.

Given a Force vs. Time graph, how do you find impulse?

area under the Force vs. Time curve.

Given a Force vs. Time graph, how do you find change in momentum?

The area under the F vs. t graph = change in momentum.

What does the slope of the Momentum vs. Time graph represent?

net force acting on the system at that moment.

You are given the equation ab=k, and several values of “a” and “b”. You label the y-axis ____ and the x-axis ____ so the slope of the line allows you to find k. Note: there is more than one correct answer to this question.

can be both a and b or b and a

You are given the equation a=kb2, and several values of “a” and “b”. You label the y-axis ____ and the x-axis ____ so the slope of the line allows you to find k. Note: there is more than one correct answer to this question.

a and b (y= mx)