I need to know how to do this. I dont just want the answer though. I need to know HOW to do it?

Question

In the following equation, if x is measured in meters and t is measured in seconds, identify the units on the variable v.

x=vt

Answer 1

What you're asking about is a thing called 'dimensional analysis'. It's a pretty good way to check your operations before you actually do any math, and it works like this:

Treat the 'unit' just as you would any other 'variable' and see if the answer you get is in the units you expect.

For example 2.54cm = 1 inch => 2.54 cm/inch = 1 (dividing both sides by 'inch')

Now 1 is a 'dimensionless' number and if you need to know how many cm in 5 inches, you say

1*5inch = 2.54cm/inch * 5 inch = 2.54*5 (cm/inch * inch)
which is 12.7 (cm*inch/inch) = 12.7 cm

Another one:

10 N of force applied to a 1.5 m lever results in
15 N*m of torque (the unit of torque is the Newton meter)

Once you get used to thinking this way, you'll never again have to ask, "Do I multiply by this constant, or divide?"

How many inches in 15 cm? 2.54 cm/inch

15*2.54 cm*cm/inch = 38.1 cm²/inch Oops.... expected inches

cm/(cm/inch) = cm*(inch/cm) = inches so
15/2.54 = 5.905 inches.

Or

60s/minute *60minutse/hr * 24hr/day = 86400 s/day

See how easy that works?


Doug

Answer 2

The general way is to write a second equation using just the units.

M=(units of v)*seconds

and just as in regular equation-solving, isolate the unknown.

Here's another example: speed=acceleration*time or v=at
(v and t are the same as above). Find the units of acceleration.

Answer 3

1. Divide both sides by t to get v by itself>> x/t=v
2. You know the units of both x and t, and since v=x/t, the units of v must be equal to the units of x/t= meter/seconds =v.

Answer 4

Speed. When you isolate v, you need to divide both sides of the equation by t, thus making it look something like this....

x/t=v

Since x is distance and t is time....we can conclude that v is speed....for the unit for speed is distance over time.... (meters over seconds)

Answer 5

just make v the subject. v= x/t, so v is measured in meter per second.

Answer 6

rewrite the equation to answer your own question:

v = x divided by t

x = vt, so v = x/t

here's how I rearranged the terms:
x = vt
x/t = vt/t
x/t = v or v = x/t.

Answer 7

(x=vt) it means that if we multiply v and t it will be equal to x.
t is multiplying with v so if we take t to the other side it will be divided by x. the equation will become
x/t=v
so here is the answer v=x/t
the method is simple multiplying REVERSE dividing
Dividing REVERSE Multiplying
Adding REVERSE subtracting
Subtraction REVERSE Adding

Answer 8

x = vt, then v = x/t
v = meters / sec

Answer 9

meters per second

Answer 10

let x be m (short for meters) and t be s (short for seconds)
So,
x = vt
m = vs
v = m/s
m/s can also be written as ms^-1