I do no understand this Math/physics formula can you please shed some light?

N

nayy z

New member
Yes its me again ! lol you'll be hearing alot from me since im learning physics online and have no way to ask questions exept for this.

The new formula i do not under stand is the solving for time formula dealing with constand acceleration.

v-vo
t= _______
a

This is in the SI system
where:
v= colocity after abject accelerates for a t
Vo= initial volocity
a= acceleration
t=time

Try and keep it simple please and step by step and if you can use it as and example in this question:
if someone asked how long it took a car to accelerate from 10 m/sec to 35 m/sec while going to the right at a constant acceleration of 5 (m/sec)/sec to the right.

Thank you
 
the formula in plain english goes like this:
Acceleration (a) equals change in velocity (V-Vo) divided by the time it took to make that change in velocity (t)

so if an object is accelerating at 5 m/s/s and increases speed from 10m/s to 35m/s how long will that take.

change in velocity = V-Vo or 35-10= 25

so: (25m/s divided by t) = 5 m/s/s; thus t = 5 s
 
Here's the entire answer and a little more description.

OK, the equation you ask about derives from our attempts to describe HOW THINGS MOVE.

If an object is moving, we want to find a way to describe HOW FAST it's moving. The term we use to describe this is called VELOCITY. Velocity describes the RATE OF CHANGE OF AN OBJECT'S POSITION WITH TIME:

v = velocity = change in position / change in time

So, for example if you're driving in a car along the highway and you look down at your speedometer and it reads "35 mph" that dial is telling you HOW MUCH DISTANCE YOU'RE COVERING PER UNIT TIME:

v = 35 mph = 35 miles / hour (i.e. how much distance / time)

So, velocity tells us how an object's POSITION changes with time.

e.g.

If a ball moves 300 feet in the time of 5 seconds, then the velocity is:

v = distance moved / time = 300 feet / 5 seconds = 60 ft/sec

If we move beyond the concept of velocity, we come to the concept of ACCELERATION. What does acceleration describe? It tells us the RATE OF CHANGE OF THE RATE OF CHANGE OF AN OBJECT'S POSITION (sounds confusing, I know). Or, equally said, IN WHAT WAY AN OBJECT'S VELOCITY CHANGES - i.e. THE RATE OF CHANGE OF VELOCITY.

So, if you're driving a car and you're traveling at 500 feet/sec and you speed up to go 750 ft/sec over a time of 5 seconds, then your acceleration is calculated to be:

a = acceleration = change in velocity / change in time = v - v0 / t

(this is the equation you mentioned in your question)

= 750 ft/sec - 500 ft/sec / 5 sec

= 250 ft/sec / 5 sec = 50 ft/sec^2

a = 50 ft/sec^2

So what the concept of acceleration is telling you "how fast your speedometer needle is moving" - i.e. how fast your velocity is changing.

To recap:

Velocity tells your THE RATE at which an object's position is changing.

Acceleration tells you THE RATE at which an object's VELOCITY is changing.

In the specific problem you give, we can solve it like this:

v0 = initial velocity = 10 m/s
v = final velocity = 35 m/s
a = acceleration = 5 m/s^2

We use the equation you supplied:

a = v - v0 / t

If we solve this equation for t (which is the term we're interested in solving for) we get:

t = v - v0 / a

= (35 m/s - 10 m/s) / 5 m/s^2

= 25 m/s / 5m/s^2

or

t = 5 seconds


So, it would take 5 seconds for the car to accelerate to those speeds.



I hope that clears things up for you. OK? Good luck learning physics!







anaGAh.
 
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