Help lol

1. Oct 30, 2006

Please someone help me with my hw :D i have tried and tried but i just suck at science

1. To turn 50g of boiling water to steam requires
A. 50 Calories (210 Joules)
B. 500 Calories (2100 Joules)
C. 540 Calories (2270 Joules)

2. If you were caught freezing in cold weather with only a candel for heat, you would be warmer in
A. an igloo
B. a car
C. a tent
D. a wooden house

3. It is possible to totally convert a given amount of energy into mechanical energy.
A. True
B. False

4. When a solid is changed to a liquid phase, the solid
A. absorb energy
B. release energy
C. neither

5. When work is done by a system and no heat added to it, the temperature of the system
A. Decrease
B. Increase
C. Remains unchanged

6. An inventor discovers a harmless and tasteless salt, which, when added to water changes its boiling point, the market value for this salt will be best if the salt
A. lower the boiling point of water
B. raises the boiling point of water
C. either raises or lowers the boiling point, as the food would be cooked either way.

7. A good asorber of radiation is a
A. good reflector

8. The amount of energy ultimately converted to heat by light bulbs is about
A. 30%
B. 60%
C. 15%
D. 45%
E. 100%

9. Steam burns are more dangerous than burns caused by boiling water becuase steam
A. Gives the additional energy when it condenses
B. Has more energy per kilogram than boiling water
C. Both of these
D. neither of these

i think number 2 is A
Number 4 is A
and number 9 is C

i am clueless about the rest :P

Last edited: Oct 30, 2006
2. Oct 30, 2006

geoffjb

This forum provides help, not answers. You must show a reasonable attempt at solving these questions. No one is going to just give you 9 answers.

3. Oct 30, 2006

i have tried books i cant stand it lol

4. Oct 30, 2006

what course is this ?

5. Oct 30, 2006

phsical science :P

6. Oct 30, 2006

1.a
2.a
3.a
4.b
5.c
6.b
7.b
8.e
9.c

please tell me wat i got rong and rite ty

7. Oct 30, 2006

geoffjb

No one is here to check your answers. If you want help with a question, show what you've tried and where you're struggling.