SCENERIO: You are working for a humanitarian aid agency that plans to air-drop supplies into a war-torn region. The political landscape is such that in order to reach the civilians in need – and not fall into the wrong hands – the supplies must land in a very precise location. The agency’s helicopters are equipped with a ramp down which bundles of supplies can be rolled as a means of launching them. The bundles of supplies are spherical and cylindrical, and come in a variety of sizes and masses. Enough friction is present on the ramp that all bundles are certain to roll without slipping as they are launched. It is up to you to determine from where on the ramp each bundle of supplies should be launched, assuming the helicopter hovers at a constant height.

QUESTION: Now assume that conditions in the war-torn region have deteriorated to the point that it is no longer safe for a helicopter to hover stationary above the ground for a supply drop. How would your answers about where to drop supplies change if they are instead released from an aircraft moving with constant velocity? With constant acceleration?

Compare the green house effect on Earth to Venus then discuss two similarities and two differences in the green house effect between Earth and Venus.

Indicate whether each quantity increases, decreases, or remains the same for the situation being described: The number of particles and volume are held constant and the gas is cooled

• How many possible directions are there for the frictional force?

• Physicists categorize the frictional force according to the relative motion between the two surfaces. What are some of the categories?

• One category of frictional forces is the static frictional force. What is the relative motion between the surfaces for this category? Describe a theory of static frictional forces.

• Another category of frictional forces is the kinetic frictional force. What is the relative motion between the surfaces for this category? Describe a theory of kinetic frictional forces.

In an experiment, 426 g of water is in a copper calorimeter cup of mass 205 g. The cup and the water are at an initial temperature of 10.9 oC. An unknown material with a mass of 361 g at a temperature of 296.1 oC is placed in the water. The system reaches thermal equilibrium at 36.1 oC. What is the specific heat of the unknown material? units = J/kg-C

Discuss the general design of light and heavy water reactors

Three children are riding on the edge of a merry-go-round that is 122 kg, has a 1.60 m radius, and is spinning at 17.3 rpm. The children have masses of 19.9, 29.5, and 40.8 kg. If the child who has a mass of 29.5 kg moves to the center of the merry-go-round, what is the new angular velocity in rpm?

A 425 kg satellite is in a circular orbit at an altitude of 400 km above the Earth's surface. Because of air friction, the satellite eventually falls to the Earth's surface, where it hits the ground with a speed of 2.00 km/s. How much energy was transformed to internal energy by means of friction?
J

1-What is the expression for the thin lens equation? Define all the terms in the expression.

2-Describe the three properties that determine the focal length of a lens.

3-Define the following:
i. Converging lens______

ii. Diverging lens_______

iii. Focal length___________

iv. Focalpoint____________

v. Object distance_______

vi. Imagedistance___

vii. Real image___

viii. Virtual image

What is the magnitude of the tangential acceleration of a bug on the rim of a 12.5-in.-diameter disk if the disk accelerates uniformly from rest to an angular speed of 75.0 rev/min in 3.50 s?
m/s²

(b) When the disk is at its final speed, what is the magnitude of the tangential velocity of the bug?
m/s

(c) One second after the bug starts from rest, what is the magnitude of its tangential acceleration?
m/s²

(d) One second after the bug starts from rest, what is the magnitude of its centripetal acceleration?
m/s²

(e) One second after the bug starts from rest, what is its total acceleration? (Take the positive direction to be in the direction of motion.)

1. Explain the difference between an elastic and inelastic collision.

2. How many times more energy is required to increase the speed of a 2200 pound car by 10 mph if car initially is going 30 mph versus it initially going 80 mph? (convert to metric)

3. how many horse power are required to accelerate from 80 mph to 90 mph in 0.75 seconds? (tell me the average horsepower. 1 horsepower = 750 watts)

4. will a solid lead cylinder float or sink in mercury? why? (Pp= 11.34 g/cm^3, Hg= 13.53 g/cm^3)

5. how many centimeters of the lead cylinder would be submerged in the mercury if its dimensions are (radius = 5cm, height = 10cm)

Identify and briefly describe the five key components of the “scientific method”

uranium-235 is used in a nuclear power plant as fuel source because