3) Contractor hires out a machine. In the first year of hiring the profit is ...

1) A ball is thrown down at 72 km h–1 speed from the top of a building. The building is 125 meters tall. The distance travelled before it reaches the ground is as follows: s= u0t + 1/2 gt^2
(a) Time for the ball to drop to fifth of the height of the building?
(b) Time for the ball to reach the ground?

2) A firm has 110 employees for the 1st week. The number rises by 6% per week. How many persons will be employed in the 20th week at current rate?

3) Contractor hires out a machine. In the first year of hiring the profit is £6000, but this diminishes by 5% in successive years. Show that the annual profits form a geometric progression and find the total of all the profit for the first 5 years?