Answer:
1/2 M V^2 = .1 M g H where 10% of PE goes into KE
V^2 = .2 g H = .2 * 9.8 * (2100 - 1600) = 980 m^2 / s^2
V = 31.1 m/s increase in speed during descent
1 km / hr = 1000 m / 3600 sec = .278 m/s
V = 31.1 m/s / (.278 m/s / km /hr)= 112 km/hr
Explanation is in the file
tinyurl.com/wpazsebu
The physical and chemical properties of metal can differ between the elements but if we try and generalize.
Physical properties are that they are hard, dense, shiny, malleable (can be bent), ductile (can be pulled into wires), a good conductor of heat and have high melting points meaning that they are solid at room temperature
Their chemical properties include being good electrical conductors, they make metallic bonds (ionic bonds with non-metals) and their atoms are arranged in a lattice. They release hydrogen when reacted with acids and are usually cations (positive ions).
The amount of energy used in the billing period is 5,400,000,000 joules.
One kWH is the amount of energy transferred in one hour, there 1 kWh is equal to
1 kWh=1*1000*(J/s)*3600 s
=3600000 J
Thus the amount of energy in joules consumed by the user for the billing period is =1500*3600000=5,400,000,000 J.
The amount of energy used in the billing period is 5,400,000,000 joules.