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:
Resultant displacement = 1222.3 m
Angle is 88.3 degree from +X axis.
Explanation:
A = 550 m north
B = 500 m north east
C = 450 m north west
Write in the vector form
A = 550 j
B = 500 (cos 45 i + sin 45 j ) = 353.6 i + 353.6 j
C = 450 ( - cos 45 i + sin 45 j ) = - 318.2 i + 318.2 j
Net displacement is given by
R = (353.6 - 318.2) i + (550 + 353.6 + 318.2) j
R = 35.4 i + 1221.8 j
The magnitude is

The direction is given by
Answer:
We see objects in a dark room due to the emission of light photons which are sensitive to our eyes. Darkness is simply a terminology used to describe the absence of light. Visible light to human is a component of the electromagnetic spectrum. Our eyes have receptors that picks the photons which light releases
Explanation:
Mass of 1 staple = 6.8 g/210 staples
mass of 1 staple = 0.032380952 g
Hope that helps!!