1. A car bought for $20,000. Its value depreciates by 10% each year for 3 years. What is the car's worth after3 years? 2. Find the perimeter of a circle whose radius is 3.5cm. (Take pi = 22/7) 3. The volume of a cone is 1540cm³. If its radius is 7cm, calculate the height of the cone. (Take pi = 22/7) 4. What is the coefficient of b in the expression b² - 5b +18 5. Expand (x +2) (9 - x) 7. Find x and y in the simultaneous equations. x + y = 4 3x + y = 8 8. Factorize a² +3ab - 5ab - 15b² 9. The bearing of a staff room from the assembly ground is 195degrees, what is the bearing of the assembly ground from the staff room?

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)