##### Physics- Acceleration

 Physics Tutor: None Selected Time limit: 1 Day

A car traveling with an initial velocity of -25 m/s changes velocity to -35 m/s in a time of 10.3s. Is the constant acceleration of the car positive or negative in this problem? Explain why.

Jun 10th, 2015

intial velocity=-25m/s final velocity=-35m/s

time=10.3

acceletion=(final velocity-initial velocity)/time

=-10/10.3

=-0.9709m/s^2

deceleration =0.9709

the acceration is negative because the vehicle is decelarating

Jun 10th, 2015

how do we know that the car is deaccelerating if our accretion number that you got is positive?

Jun 10th, 2015

the number i got acceration is negative -0.9709

this negative sign means it is decerating  when giving answers in decerating you do not include negative sign

Jun 10th, 2015

Oh i apologize i didn't see the negative sign. Thank you so much for the help.

Jun 10th, 2015

Can you help me with a different question?

Jun 10th, 2015

yes

Jun 10th, 2015

A car traveling with an initial velocity of -25 m/s comes to a stop in a time of 6.3s. Is the constant acceleration of the car positive or negative in this problem? Explain why.

Jun 10th, 2015

when the car comes to rest its final velocity  will be zero

acceleration=change in velocity/time

a=(0--25)/6.3

=4.167m/s^2

the acceleration  is by positive because negative multiply negative is a positive

best me my friend

Jun 10th, 2015

Thank you so much! I really appreciate it

Jun 10th, 2015

you re welcomed happy to serve you if you have even questions in mathematic feel free to ask

Jun 10th, 2015

Jun 10th, 2015

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Jun 10th, 2015
Dec 8th, 2016
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