A two part calculation dealing with the required volume of helium to lift a balloon.

A. A helium filled balloon is to lift a load of 2000 kg. The mass of the empty balloon itself is 150 kg. Calculate the minimum volume of helium needed to fill the balloon to produce the required lift. P air=1.28kg/m^3 P He=0.179kg/m^3 B. If the volume of the balloon is made 20% larger than that required in part A, what w ...continues

multiple choice

1) Which of the following equations describes an oscillating system moving through its equilibrium, position at t=0? a.x=A cos (wt) b.x=A sin (wt) c.x=wAcos(wt) d.x=w^2Asin(wt) 2)Fluid moving through a pipe may experience changes in certain physical parameters. Which of the following will not change under any circumstance ...continues

short questions

1)how do you convert gauge pressure to absolute pressure? 2)What is Bernoulli's principle regarding pressure and fluid speed? 3)The moment arm used to calculate the magnitude of torque is defined as? 4.young's modulus is the ratio of? 5.An object will float in liquid if: a.its full volume displaces more liquid than it weigh ...continues

Determining the minimum escape velocity required to get a rocket out of an orbit.

A rocket is in an elliptic orbit around the earth. To put it into an escape orbit, its engine is fired briefly, changing the rocket's velocity by (delta) V. Where in the orbit, and in what direction, should the firing occur to attain an escape with a minimum value of (delta) V?

Calculating how high a projectile fired from Earth's surface rises.

A projectile of mass m is fired from the surface of the earth at an angle A from the vertical. The initial speed Vo is equal to the square root (GMe/Re). How high does the projectile rise? Neglect air resistance and the earth's rotation. (Hint: It is probably easier to apply the conservation laws directly instead of using orbit ...continues

Performing the calculations required to move a vehicle from one circular orbit to another.

A space vehicle is in a circular orbit about the earth. The mass of the vehicle is 3,000 kg and the radius of the orbit is 2Re= 12,800km. The vehicle must be transferred to a circular orbit of radius 4Re. a) What is the minimum energy expenditure required for the transfer? b) An efficient way to accomplish the transfer is ...continues

Determining the distance of Halley's Comet from the sun at perihelion and aphelion and its speed when closest to the sun.

Halley's comet is in an elliptic orbit about the sun. The eccentricity of the orbit is 0.967 and the period is 76 years. The mass of the sun is 2 x 10^30 kg and G=6.67 x 10^-11 Nm^2/kg^2. a) Using this data, determine the distance of Halley's Comet from the sun at perihelion and at aphelion. b) What is the speed of Halle ...continues

Calculating the energy that will make the motion circular and finding the frequency of radial oscillations.

A particle of mass m moves under as an attractive central force Kr^4 with angular momentum l. For what energy will the motion be circular, and what is the radius of the circle? Find the frequency of radial oscillations if the particle is given a small radial impulse.

Needing help for a problem of friction

A half section of pipe, weighting 200 lb, is to be moved to the right along the floor without tipping. Knowing that the coefficient of friction between the pipe and the floor is 0.40, determine the largest allowable value of «alpha». My part of the answer: Sum Fy=0 -200 + N + T*sin(alpha)= 0 N = 200 - T*sin(alpha) Su ...continues

Problem of friction

Here is the asking problem relating to the cylinder drawing: Find the moment of the largest couple M which may be applied to the cylinder if it is not to spin. The cylinder has a weight W and a radius r, and the coefficient of static friction (Us) is the same at A and B. I give you the answer of this problem: M=W*r*Us*(1+Us) ...continues