If something is going down a hill it can help slow it down
it can stop you from flying off a rollercoaster
Answer:
7.9
Explanation:
When we put the metal piece in the liquid (which is in the graduated cylinder), how much it goes up is equal to the volume of the piece we inserted.
So now we know that the volume of that piece of unknown metal is 7mL (which is the same as 7).
Density is .
So the density of that piece of metal is
Which leaves us with a final density of 7.9
Send wave from your location to the object and wait until echo is back.
Measure the time taken.
If you know the speed of wave (say sound wave), than just multiply by half time taken wave to return
Answer: 27.21 V
Explanation:
The <u>electric potential</u> due to a point charge is expressed as:
Where:
is the <u>electric constant</u>
is the <u>electric charge of the hydrogen nucleus</u>, which is positive
is the <u>distance</u>
Rewritting the equation with the known values:
Finally:
a). for velocity, you must have a number, a unit, and a direction.
Yes. This one isn't bad. The 'number' and the 'unit' are the speed.
b). the si units for velocity are miles per hour.
No. That's silly.
'miles' is not an SI unit, and 'miles per hour'
is only a speed, not a velocity.
c). the symbol for velocity is .
You can use any symbol you want for velocity, as long as
you make its meaning very clear, so that everybody knows
what symbol you're using for velocity.
But this choice-c is still wrong, because either it's incomplete,
or else it's using 'space' for velocity, which is a very poor symbol.
d). to calculate velocity, divide the displacement by time.
Yes, that's OK, but you have to remember that the displacement
has a direction, and so does the velocity.