Vivian Said:

Science help!!!!?

We Answered:

3. evaporation takes energy, therefore it is endothermic
evaporation is a cooling process so the wet clothes will be cooler than the dry ones.

5. Fries have water in them. As they are put in the hot oil the water immediately boils off.

Valerie Said:

easy 7th grade multiple choice science questions? Please help!?

We Answered:

yepp....
those are right ;]

are those for ms.gezzi???

Terrence Said:

Grade 10 Science - Balancing Equations?

We Answered:

ok so all you really have to do is look at the equation and add/multiply integers so that each side of the reaction (either side of the --> sign) has the same number of atoms

Na has a 1+ charge and O(2) has a 2- charge, the charges have to cancel to make a compound, making Na(2)O

now here are some steps to balance the equation:

1: look at the equation:
the left side is the reactants and the right side is the products
Na + O(2) --> Na(2)O
there are 2 oxygen atoms on the reactant side and 1 oxygen atom on the product side. you have to multiply Na(2)O by 2 so that there are 2 oxygen atoms on both sides.
the equation will look like this:
Na + O(2) --> 2Na(2)O

2: finish balancing:
so far the oxygen atoms are balanced, now you have to balance to sodium. on the reactant side you have one Na atom and on the product side you have 4 Na atoms. to balance this you multiply the Na on the reactant side by four.

your final balanced equation should look like this:
4Na + O(2) --> 2Na(2)O

Margaret Said:

9th grade science questions? (with formulas)?

We Answered:

'Lo.
Question 1!
acceleration = final velocity - initial velocity / time

60-15= 45 Take the beginning speed and subtract from ending speed.

45/12= 15/4 Take that and divide by time.

Answer: 15/4 m/s/s

distance = initial velocity * time + 1/2 acceleration * time^2

d=(15*12)+(1/2)(15/4)(12^2)
d= 180 + (15/8)*144
d= 180+270
d= 450

It moved with an acceleration of 15/4 m/s/s to a distance of 450 meters.


Question 2!

acceleration = final velocity - initial velocity / time

20=(fv-5)/3

20 *3= (fv-5)/3 *3

60=fv-5

65=fv

distance = initial velocity * time + 1/2 acceleration * time^2

d= 5*3+ 1/2*20*3^2

d=8+ 1/2*20*9

d= 8+90

d=98

The car moved with a final speed of 65 m/s and to a distance of 98 meters :).

Just plug the numbers into the formulas, they seem to work :D.