After discovering that two hikers have been stranded on Devil's Thumb Pass, the Colorado Search and

Rescue team sends out a plane with supplies for the hikers. Because the hikers are in an isolated location, the

plane has to drop the supplies as it ies overhead. If the plane is 235 m above the hikers and

has a horizontal speed of 200 km/h, how far away from the hikers should the supplies be dropped if they are

to land at the hikers' location? (Hint: the initial y-component of the supplies' velocity is zero

(a) Two point charges totaling 7.50 µC exert a repulsive force of 0.150 N on one another when separated by 0.812 m. What is the charge (in µC) on each? smallest charge in µC largest charge in µC

(b) What is the charge (in µC) on each if the force is attractive? smallest charge in µC largest charge in µC

A car initially traveling at 25.7 m/s undergoes a constant negative acceleration of magnitude 1.80 m/s² after its brakes are applied.

(a.) How many revolutions does each tire make before the car comes to a stop, assuming the car does not skid and the tires have radii of 0.340 m? (rev)

(b.) What is the angular speed of the wheels when the car has traveled half the total distance? (rad/s)

A softball is hit over a third baseman's head with speed v0 and at an angle θ from the horizontal. Immediately after the ball is hit, the third baseman turns around and runs straight back at a constant velocity V=7.00m/s, for a time t=2.00s. He then catches the ball at the same height at which it left the bat. The third baseman was initially L=18.0m from the location where the ball was hit at home plate.  

1) Find a vector expression for the velocity v⃗  of the softball 0.100 s before the ball is caught.

Use the notation vx, vy, an ordered pair of values separated by a commas Express your answer numerically in meters per second to three significant figures.

2) Find a vector expression for the position r⃗  of the softball 0.100 s before the ball is caught.

Use the notation x, y, an ordered pair of values separated by a comma, where x and yare expressed numerically in meters, as measured from the point where the softball initially left the bat. Express your answer to three significant figures.

The coefficient of expansion for liquids is:

a) greater than that for solids

b) different for different temperatures

c) smaller as the volume changes

d) greater as the volume changes

What is the difference between phase velocity and phase angle?

What theoretical explanations exist for the fact that there are three generations of leptons and quarks?

I'm not so much asking why there are exactly 3 generations, but rather what makes electron, muon and tau differ. Also, since the three families of quarks don't have to be a priori related to the three families of leptons, I'm interested in answers for either quarks, leptons, or both.

3. A cube of Brass (B = 70 GPa) measuring 1.0 m on each side is submerged under water. It is lowerd to a depth where a force "F" is acting perpendicularly into each side, reduces the cube's volume by 1.8 %.

(a) Calculate the size of this force.

2.A researcher examines a piece of fresh human cartilage, with an area of 1.9 cm2. She observes that when subjected to a tensile force of 194 N it stretches by 4.8 %.

(a) Calculate the elastic modulus of cartilage.

1. A student pushes on the end of a helical spring, which in turn presses a 1.25 kg, wooden block onto a vertical wall. The coefficient of static friction between the block and wall is 0.5. She compresses the spring 5.2 cm.

(a) Calculate the minimum spring constant necessaary to prevent the block from sliding down the wall.

1. Explain the physical reason that this change in Planck's expression avoided the ‘Ultraviolet Catastrophe’.

2. Calculate the probability of finding the particle within the finite wall of the box when the particle is in the lowest and highest bound energy states of the box with one finite wall described above. Assume that the coefficient D is approximately D= (2/L)^1/2

Every second at a particular waterfall, some 6996 m³ of water falls a distance of 37 m. What is the increase in entropy in kJ/K, per second due to the falling water? (Assume a 23°C environment).

part a ) A person throws an object with mass m nearly vertically with an initial momentum p=(px,py,pz). With respect to the cartesian coordinate system where the person is looking in the direction y, with x directed to their right. Let ∝ be the elevation angle of the initial momentum (with respect to the x-y plane) and let θ be the angle of the initial momentum with respect to the y-z plane. Write parametric equations for the trajectory of the center of mass of the object.

part b) How high would the object need to be thrown if three objects are to be juggled at 120 beats per minute (each object is thrown in turn one at a time and one per beat) with a horizontal displacement of approximately 0.30 m? use g = 9.81.

what is the discussion and conclusions for the trajectories physics lab?

A shot putter threw a shot at an angle of 43o above the horizontal from a height of 2.0 m above the ground. The shot traveled 19.0 m horizontally from the launch position. (a) What was the initial speed of the shot when it left the shot putter’s hand? (b) How long was the shot in the air? {13.0 m/s, 2.0 s}

OSHA, the Occupational Safety and Health Administration, has established shandards for workplace exposure to noise. According to OSHA's Hearing Conservation Standard, the permissible noise exposure per day is 93.0 dB for 4 hours or 103 dB for 1 hour. Assuming the eardrum is 9.5 mm in diameter, find the energy absorbed by the eardrum, when subjected to each of these conditions.

(a) 93.0 dB for 4 hours

(b) 103 dB for 1 hour

(c) Is OSHA's safety standard simply a measure of the amount of energy absorbed by the eardrum?
Y or N
Explain.