Unfortunately, the question is so vague it can't be answered specifically. But I will use my intuition and say that you are a high-school student studying algebra-based physics and are now up to the chapter or unit on rectilinear motion. If so, read on. If not, well, then perhaps you could use the discussion page to add more info (and maybe rephrase the question). The general formula for straight-line motion is a quadratic equation. Displacement (or distance) is expressed as a function of time. In other words, dispacement is the dependent variable and time is the independent variable. But displacement is also dependent upon the values of initial displacement, initial velocity, and acceleration, which are all coefficients of the general displacement formula. Here is the formula: d = d0 + v0t + (1/2)at2, where d is the displacement, d0 is the initial displacement (in other words, the displacement at t = 0), v0 is the initial velocity (velocity at t = 0), and a is the acceleration. So, using the formula, you can solve for distance traveled (displacement) if you know the values of all those parameters to the right of the equal sign. But what if you don't know the value of t? Well, in that case, you had better know the values of all the other parameters, including the d to the left of the equal sign. If you know the initial distance, the total distance traveled, the initial velocity, and the acceleration, you can solve for t. Usually, we set up our frame of reference so that d0 = 0. Frequently, v0 = 0, also. (In other words, the object has no initial displacement and no initial velocity.) If you know the distance traveled, d, and the acceleration, a, then you can solve for t using the simplified formula d = (1/2)at2. Solving for t, you get t = SQRT(2d/a).Since you now know t and d, you can calculate the object's average velocity using the formula, va = d/t. Since the object started at rest (it had zero initial velocity), its final velocity, vf, is 2va. You might be able to use the equation of motion v2 = u2 + 2ad, where v is the final velocity, u is the initial velocity, a is the acceleration & d is the distance covered. Quite often the initial velocity is zero, so the equation simply becomes v2 = 2ad. So the final velocity v =SQRT(2ad).
You do need some data to find the acceleration.
You do need some data to find the acceleration.
You do need some data to find the acceleration.
You do need some data to find the acceleration.
Let's see if we understand this. You get a monster question on a Physics test,
and it says:
A body moving in a straight line started out at the speed of 'S' and accelerated
at the rate of 'A'. What was its speed after it covered the distance of 'D' ?
That's how we understand your question. Here's how we'd approach it:
At any time 'T', its speed is [ S + A T ].
Over that whole period of time, its average speed is
1/2 (original speed + final speed) = 1/2 (S + S + A T) = S + A T/2
The distance it covers during that time is
(average speed) x (time) = (S + A T/2) x (T) = 1/2 A T2 + S T
and the distance you're interested in is 'D'. After covering the distance of 'D',
D = 1/2 A T2 + S T . . . or . . . 1/2 A T2 + S T - D = 0
There's a nice, friendly quadratic equation, like hundreds you've solved before.
It looks scary at first, because there are so many letters in it, but there's only
one letter there that you don't know. You know A, S, and D, so you can put
numbers in for them. 'T' is the only number you don't know ... the time the
object took to cover the distance of 'D'. Solve the quadratic equation for 'T'.
You'll know how long it took, and then, knowing that the final speed is 'S T',
you'll also know the final speed.
One formula that can be used - assuming constant acceleration, of course! - is vf2 = vi2 + 2as, where vf is the final speed, vi is the initial speed, a is the acceleration and s is the distance. In your case, solve for final velocity.
Since you cannot use the time ... because it's not given ... you must use
the information that IS given, to calculate the initial velocity. It will most
likely include things like the final velocity, the acceleration, the change in
momentum, the change in kinetic energy, etc.
I can't tell you exactly how to do it, because I don't know what's given,
and even that could change from one problem to the next. But I can give
you the general approach, which will stand you in good stead no matter
what. The golden approach is:
Do not dwell upon that which is not given, but rather, turn
your attention, with gratitude, to that which is given.
Assuming you also know the final velocity and acceleration over the displacement then the initial velocity is
Vinitial = (Vfinal2 - 2*acceleration*displacement)0.5
You do need some data to find the acceleration.
There is average velocity, and there is instantaneous velocity. I don't think "overall velocity" is a concept generally used in physics; please clarify what you mean.
You use the information you're given, along with the equations and formulas you know that express some kind of relationship between the information you're given and the initial and final velocity.
Velocity is defined asv = dx/dtwhere:v is velocity;dx is displacement;and dt is elapsed time.Assuming velocity is constant, then displacement is calculated as:dx = v/dt.
The force-displacement graph for the strings of a new type of graphite-head tennis racquet is shown in diagram (a). The racquet is tested in a laboratory by being secured vertically and then having a special type of non-deforming tennis ball fired at it horizontally, as shown in diagram (b). The initial velocity of the ball as it strikes the racquet is 10 m s-1 east. After striking the racquet, the ball has a velocity of 9.5 m s-1 west. The mass of the ball is 100 g. What is the maximum displacement of the strings of the racquet during this interaction?
You can't. "I traveled 100 miles and finished at a speed of 40 mph. What was my starting speed ?" Impossible without another piece of information. Something like the length of time the trip took, or the acceleration during the trip. Something like that.
Kinematics. Final velocity squared = initial velocity squared + 2(gravitational acceleration)(displacement)
vf2 = vi2 + 2ad, where vf is final velocity, vi is initial velocity, a is acceleration, and d is displacement. Solve for a.vf = vi + at, where t is time time. Solve for a.
You use the information you have.We could be a lot more specific if you had told us what you do have,instead of telling us only what you don't have.
You cannot.
Use the formula Acceleration = (final velosity - initial velocity)/ time.
v = 2s/t - u where u=initial velocity, v=final velocity, s = distance and t = time
There is average velocity, and there is instantaneous velocity. I don't think "overall velocity" is a concept generally used in physics; please clarify what you mean.
There is not enough information to calculate the answer.
vf2 = vi2 +ad, where vf is the final velocity, vi is the initial velocity, a is acceleration, and d is displacement. In physics, velocity is the change in position of an object over a given time interval, and change in position is displacement, rather than distance. To find displacement, manipulate the equation in the following manner. Assume vi is zero. vf2 = 0 + 2ad vf2 = 2ad vf2/2a = 2ad/2a vf2/2a = d
Without distance, you have to know time, initial velocity, and acceleration, in order to find final velocity.
You use the information you're given, along with the equations and formulas you know that express some kind of relationship between the information you're given and the initial and final velocity.
You can't. You need either the final velocity or the acceleration of the object as well, and then you can substitute the known values into a kinematics equation to get the initial velocity.