Answer:
Explanation:
using the law of the conservation of energy:
where K is the spring constant, x is the spring compression, N is the normal force of the block, 
is the coefficiet of kinetic friction and d is the distance.
Also, by laws of newton, N is calculated by:
N = mg
N = 3.35 kg * 9.81 m/s
N = 32.8635
So, Replacing values on the first equation, we get:
solving for :
To solve this problem, we should recall the law of
conservation of energy. That is, the heat lost by the aluminium must be equal
to the heat gained by the cold water. This is expressed in change in enthalpies
therefore:
- ΔH aluminium = ΔH water
where ΔH = m Cp (T2 – T1)
The negative sign simply means heat is lost. Therefore we
calculate for the mass of water (m):
- 0.5 (900) (20 – 200) = m (4186) (20 – 0)
m = 0.9675 kg
Using same mass of water and initial temperature, the final
temperature T of a 1.0 kg aluminium block is:
- 1 (900) (T – 200) = 0.9675 (4186) (T – 0)
- 900 T + 180,000 = 4050 T
4950 T = 180,000
T = 36.36°C
The final temperature of the water and block is 36.36°C
Answer:
Let No be initial no of atoms
N = N0 / 2 after 1 half-life
N = N0 / 4 after 2 half-lives
So after 2 half-lives 20 of the 80 atoms remain
To determine the diameter of the earth in metres first multiply the original value by 2.
6378 X 2 = 12 756 km.
Then convert km - m
1 km = 1000 m
12 756 km = ? m
12 756 • 1000 = 12 756 000 = 12 756 000 m or 1.2756 X 10 ^ 7 m
The final solution for the diameter is 1.2756 X 10 ^ 7 m.
