Physics Help! - Topic

Azrad

Member

Posts: 10,812

Joined: Oct 15 2009

Gold: Locked

Warn: 20%

#11

Nov 2 2013 08:10am

Quote (Stolem @ Nov 2 2013 06:51am)

Item #4 Part A
Velocity differs from speed in that velocity indicates a particle's __________ of motion.
Enter the letter from the list given in the problem introduction that best completes the sentence.

I don't know what your choices are, but speed is just a scalar (a number), velocity is a scalar + a direction, or you could say velocity is speed + a direction.

Quote (Stolem @ Nov 2 2013 06:51am)

Item #4 Part G
Identify the following physical quantities as scalars or vectors.
Scalar Quantity & Vector Quantity
Choices: Position, Velocity, Displacement, Speed, Acceleration, Average velocity, Distance.

position is a vector, velocity is a vector, displacement is a vector, speed is a scalar, acceleration is a vector, average velocity is vector, distance is a scalar

Stolem

Member

Posts: 60,367

Joined: Aug 5 2007

Gold: 20.66

#12

Nov 2 2013 08:15am

Quote (Azrad @ Nov 2 2013 02:10pm)

I don't know what your choices are, but speed is just a scalar (a number), velocity is a scalar + a direction, or you could say velocity is speed + a direction.

position is a vector, velocity is a vector, displacement is a vector, speed is a scalar, acceleration is a vector, average velocity is vector, distance is a scalar

position
direction
displacement
coordinates
velocity
acceleration
distance
magnitude
vector
scalar
components

Azrad

Member

Posts: 10,812

Joined: Oct 15 2009

Gold: Locked

Warn: 20%

#13

Nov 2 2013 08:17am

Quote (Stolem @ Nov 2 2013 06:51am)

Item #5 Part A
The location of a moving particle at a particular time is given by x=at−bt2, where a = 11m/s and b = 0.70m/s2 .
Where is the particle at t = 0?
Express your answer using two significant figures.

In the future please write "t squared" as "t^2" not "t2", "t2" means t*2....
x=at−bt^2
x(0) = a*0 - b*0^2
x(0) = 0.0

This post was edited by Azrad on Nov 2 2013 08:20am

Azrad

Member

Posts: 10,812

Joined: Oct 15 2009

Gold: Locked

Warn: 20%

#14

Nov 2 2013 08:19am

Quote (Stolem @ Nov 2 2013 07:15am)

position
direction
displacement
coordinates
velocity
acceleration
distance
magnitude
vector
scalar
components

clearly the answer is direction

TritonV8

Member

Posts: 15,275

Joined: Sep 30 2009

Gold: 1,790.00

#15

Nov 2 2013 08:21am

#8 a:

first convert 50 mph to meters/second: 50 mph = 22.352 m/s
average acceleration = (change in velocity)/(change in time) = (22.352 - 0)(m/s) / (3.9 - 0)s = 5.73 m/s^2

This post was edited by TritonV8 on Nov 2 2013 08:22am

Azrad

Member

Posts: 10,812

Joined: Oct 15 2009

Gold: Locked

Warn: 20%

#16

Nov 2 2013 08:27am

Quote (Stolem @ Nov 2 2013 06:51am)

Part B
The location of a moving particle at a particular time is given by x=at−bt2, where a = 11m/s and b = 0.70m/s2 .
What is the particle’s displacement for the time interval t1 = 2.4s and t2 = 4.2s ?
Express your answer using two significant figures.

x{2.4} = 11*2.4 - 0.7*2.4^2
x{2.4} = 22.368

x{4.2}= 11*4.2 - 0.7*4.2^2
x{4.2} = 33.852

x{4.2} - x{2.4} = 33.852 - 22.368

11.484 ≈ +11 meters
(the plus is to give us a direction)

This post was edited by Azrad on Nov 2 2013 08:30am

nlin

Member

Posts: 5,728

Joined: Jun 22 2012

Gold: 0.04

#17

Nov 2 2013 01:39pm

seems like you got the help you need!

Go Back To Homework Help Topic List