1. Bronze is made by mixing molten copper and tin. If 100kg of the mixture contains 80% by mass of copper and 20% by mass of tin, calculate the density of bronze. (density of copper is 8900kgm
and density of tin is 700kgm?
(4mks
2. An astronaut weighs 900N on earth. On the moon, he weighs 150N. calculate the moon's
gravitational strength
(4mks
3. A spring stretches by 6cm when supporting a load of 15N. what load would make the spring
extend by 25mm
(4mks
A force of 100N is applied to an area of 100mm? What is the pressure exerted on the area in SI
units?
(4mks

Oxygen and hydrogen gas are at the same temperature t.what is the ratio of kinetic energies of oxygen molecule and hydrogen molecule if oxygen is 16 times heavier than hydrogen.

Calculate the ratio of h+ ions to oh– ions at a ph = 6. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 6. are they the same? why or why not? record your explanation in table a. what is the concentration of h+ ions at a ph = 6? mol/l what is the concentration of oh– ions at a ph = 6? mol/l what is the ratio of h+ ions to oh– ions at a ph = 6? : 1

The number of passengers who arrive at the platform of a subway station for the 10 am train is a random variable with a mean of 120 and a variance of 16. find the lower bound of the probability that there will be between 100 and 140 passengers (round off to second decimal place).