- #1

- 5

- 0

**Help needed, started my course late!!**

Hi everyone, I'm new to the forum and am wondering if anyone could answer these questions for me and explain them. I understand that it's very ignorant for this to be my first post, but would greatly appreciate it. Even if you can't or don't have the time to explain it, just the answers would be great....Thanks ?They're the only two I can't get.

i)4400 J of energy are used to heat a 1kg metal block by 16°C. What is the specific heat capacity of the metal?

ii) a 1.5kg aliminium kettle contains 1.5kg of water at 20°C. If the kettle element supplies 2000J/s, how long will it take to heat up 50 degrees ? (Specific heat capacity of aliminium = 900J/(kg°C) specific heat capacity of water is 4200J/(kg degree C)

2. A spring of natural length 15cm is stretched to 18cm when a mass of 50g is attached. (g=10m/s ²)

i) calculate the new length of of the spring if a mass of 225 g is attached (assuming the spring does not exceed its elastic limit). Also define the term elastic limit.

ii) Two such springs are used side-by-side to support the same 225 g mass, calculate the extension of each.

Many many thanks in advanced, I'm only back at education this year and everything is rusty.

I should also add that my physics teacher has been helping me get slowly and surely back into this, but he is off this week. These two questions are the only ones I can't get as there was a practical exam set out for both of them, and as previously said I started the course late and missed them. Many thanks in advanced.