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.
Top of the U ramp: potential energy is the highest, while kinetic energy is the lowest
Bottom of the U ramp(aka the curve part): potential energy is the lowest and the kinetic energy is the highest
THEREFORE, PE and KE have an INVERSE RELATIONSHIP.
Explanation:
내가 좋은 사람이 필요하고 내가 믿을 수 있는 사람이 필요하기 때문에 친구가 없다고 말하는 사람은 거의 없지만 대부분은 가짜이고 한국어를 모릅니다.
Answer: 
Explanation:
When a number is written in scientific notation (representing the number using powers of base ten) it is expressed so that it contains a digit in the place of the units and all other digits after the decimal point, multiplied by the respective exponent.
Then, the significant figures (or significant digits) will be the digits that are before the power of ten.
Now, in the case of the number 299,792,458 if we want to write it with three significant digits, we have to write it in scientific notation as:
The five planets that you can see from Earth without a telescope are Mercury, Venus, Mars, Jupiter and Saturn.
