I need help with these physics questions?

Question

1. A force of 5.00 N is applied to a spring whose elastic constant is 0.250 N/cm. Its change in length is?

2. What is the work required to raise a 10. kg object from the surface of the Earth to a height of 2.0 m?

3. Fifteen grams of substance X at 95 degrees Celsius is mixed with 45 grams of substance Z at 85 degrees Celsius in a container which was originally at 25 degrees Celsius. Neglecting any transfer of heat to the environment, the temperature at the end of 15 minutes was 32 degrees Celsius. What is the equilibrium temperature?

4. The melting point of substance X is -20 degrees Celsius and the boiling point is 90 degrees Celsius. How many Celsius degrees are there between the melting point and the boiling point?

5. A temperature of 50.0 degrees Celsius is the same as a Kelvin temperature of approximately

6.Laura is a star runner of the school's track team. During a trial, her speed was measured to be 9.80 m/s. If Laura’s mass is 45.2 kg, her kinetic energy during the trial?

Answer 1

1) F=-kx so x=20 cm

2) Work = Force * distance = 10 * g * 2 = 20 G Joules = 200 J (if you use 10m/s^2 for g).

3) Uh, 32 degrees.  If not, you would have no way to find out with such limited data.

4) 90--20 = 110 degrees Celcius

5) Kelvin = Celcius + 273.15 (most teachers use 273)...so 323 Kelvin (never say degrees Kelvin...it is not correct).

6) 1/2 m v^2 + Kinetic energy, so...

2171 Joules

-Fred