August 2016

A parachutist is falling with speed 176 ft/s when his parachute opens. If the air resistance is Wv2/225 lb where W is the total weight of the man and the parachute and v is in ft/s, find his speed as a function of time after the parachute opens.

If I use the suvat equations, the given resistance is the value of my what? Or I can't use the suvat equations at all?

If I use Fresultant=Fapplied-Fresistance. I can substitute the given resistance, but what would be the value or formula for getting my Fresulant and Fapplied?

Orthogonal Trajectories
y^3 - 3 = ln |Cx|

Please check if the answer I solved is correct.
My answer: y(3x^2 + c)=2

Let $x$ be a real number that satisfy the equation

$4^x + 6^x = 9^x$

What is the value of $\left(\dfrac{2}{3}\right)^x$ ?

Find the differential equation of all circles with fixed radius and the centers are on the x-axis.
Please po :'(

A constant horizontal force of 10 lb rests on a body of smooth horizontal plane. The body starts from rest and is observed to move 250 ft in 5s.
a). What is the mass of the body?
b). If the force ceases to act at the end of 5s, how far will the body move in the next 5s?

Juan plans to raise a new building of 1 million. He raise the building by issuing 10%, 20 yr bond that would pay one hundred fifty thousand interest per year an repay the amount of maturity he can least it for Php 140,000 per year. First payment being due one year from now. The building has an expected life of 20 yrs. ignoring effects on income tax, what is the difference between buying the building and leasing it?

Electric Circuits

Please solve completely. Thank you.

An RL circuit has the following values: R=550 ohms, L=4 henrys and Esub0=110 volts. If i(0)= 0 in the circuit, when does the current reach 90% of its limiting value?

Mechanics Problem. I need it tomorr before 7 am. Thank you.

A ball is thrown upward with an initial velocity of 49 m/s. Find the velocity after 3 seconds. Find its maximum height. Compute the time it takes for the ball to return to its original point. Use g= 9.81 m/s^2 .

Can someone give me a link or teach me some ODE (ordinary differential equations) based on real life situations? Thanks!