A ball was tossed from a height of 1.20 m, initial velocity of 13.0 m/s at an angle 26.0° above the horizontal. The ball hits the ground at a horizontal distance of 20.0 m from the launch point. Use 10.0 N/kg for g.

a) Find in m/s the magnitude of the velocity of the ball when it is at the top most position of its trajectory

b) Find in m/s² the magnitude of the acceleration of the ball when it is at the top most position of its trajectory.

c) How long in seconds is the ball in flight?

d) What is in m/s the magnitude of the velocity with which the ball hits the ground?

e) What is in m the highest point relative to ground reached by the ball?

According to the Guinness Book of World Records,the longest home run ever measured was hit by Roy

3)

A car turning in a circle is acceleratring in the centripetal direction, even if the speed is constant. This centripetal acceleration is the cause of a radially inward directed net force. On a level road this net force is the friction force acting from the road on the tires. You already looked at examples for this.

On racetracks and also highway turns the reliance on friction can be reduced by "banking" the road. This also reduces the risk of the vehicle to roll over. The picture shows two cars and a bus in an extremely banked turn at the Mercedes test track.

Draw a free-body diagram for a car in a banked curve. Then find an expression for the speed at which a car can negotiate the turn without any friction in the radial direction (f=0).

Calculate that speed (in mph) for a 47 m radius turn that is banked by 5 degrees.

4)

You just should have already derived an expression for the "frictionless" speed of a car in a banked turn. Now assume that the coefficient of friction is u_s. Find an expression for the maximum speed at which a car can drive through a turn with radius R and banking angle theta.

Evaluate your answer: test whether in the two limiting cases of "no friction" and "level road" your answer will turn into the two results you already have derived for these cases.

Below answer with the maximum speed (in mph) for a turn with radius 126 m, banking angle 10 degree, and coefficient of static friction 0.71.

Please help I have tried so many times I'm almost out of tries!

Steam can cause more serious burns than water at the same temperature. Here we examine this effect quantitatively, noting that flesh becomes badly damaged when its temperature reaches 50.0

A 720-kg two-stage rocket is traveling at a speed of 6.90×10^3 m/s away from Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move with a speed of 2.10×10^3 m/s relative to each other along the original line of motion.What is the speed of each section (relative to Earth) after the explosion? R/= v1=5850, v2=7950. How much energy was supplied by the explosion? [Hint: What is the change in kinetic energy as a result of the explosion?] R/= 3.97*10^8 J. Could somebody help me to know why the answer to C is 3.9*10^8J?

he K series of the discrete x-ray spectrum of tungsten contains wavelengths of 0.018 5 nm, 0.020 9 nm, and 0.021 5 nm. The K-shell ionization energy is 69.5 keV. (a) Determine the ionization energies of the L, M, and N shells.

Explain how sound is actually a form of energy. In what medium do sound waves travel? 1-2 paragraphs

A very long uniform line of charge has charge per unit length 4.74?C/m and lies along the x-axis. A second long uniform line of charge has charge per unit length -2.46?C/m and is parallel to the x-axis at y1 = 0.404m .

What is the magnitude of the net electric field at point y2 = 0.218m on the y-axis?

What is the direction of the net electric field at point y2 = 0.218m on the y-axis?

What is the magnitude of the net electric field at point y3 = 0.620m on the y-axis?

What is the direction of the net electric field at point y3 = 0.620m on the y-axis?

1. A sled of mass m is pushed for 5 seconds at a constant force. A sled of mass M (more) is also pushed for 5 seconds. THe force is the same in each case. WHat is the momentum of each sled? How do they compare? What is the energy of each sled? How do they compare?

2. The same question, except that each sled is pushed for 5 meters instead of 5 seconds.

You should be able to answer the following questions after studying “Error Analysis of a

Statistical Sample”, found in the Appendices.

a) What is the difference between “random uncertainty” and “systematic uncertainty”?

Provide examples of each.

b) How do you calculate the uncertainty in a set of values that fluctuate randomly about

some mean value?

c) What is the formula for the standard deviation of a sample? What information does the

standard deviation of a set of data provide?

d) What is meant by the phrase “Confidence Interval”?

e) Why is standard deviation used in conjunction with calculating the mean (average) of a

set of data?

LED Lighting BASIC PHYSICS:

a) Give typical forward I-V curves for R-G-B LEDS. Be specific in your three explanations and use manufacturers spec sheets. Also explain why LED lights are both Hg (think bulb breakage effects and land fill issues with dead fluorescent bulbs) and UV free as compared to fluorescents. UV rays cause colors to fade in retail clothing stores, art work to fade in museum lighting and UV accelerates the rancidity of meat fat. UV accelerates the rancidity of meat fat.

b) Explain how and why LED emission takes place over a small solid angle or in simple terms in beam like and unidirectional. Use manufacturer spec sheet plots of emission angles. In contrast fluorescent and incandescent light is omni-directional spread evenly over all 4π sterradians.

A rigid massless rod is rotated about one end in a horizontal circle. There is a load of mass m attached to the center of the rod, and one of mass M attached to the outer end of the rod. The inner section of the rod sustains a tension that is three times as great as the tension that the outer section sustains. The mass ration of m/M is?

Answer is 1

WHY?

(a) Using the definition of the scalar product, find the angles between the following pairs of vectors.

A = 2 i + 3 k and B = - 3 i - 3 j - 5 k    ___°
A = - 5 j and B = - 3 i - 4 j - k    ___°
A = 5 i + 5 j and B = 4 i + 4 j + 2 k    ___°

(b) For A = 2 i + j - 3 k, B = - 2 i + 5 j + 3 k, and C = 2 j - 3 k, find C·(A - B) to three significant figures. ___

Newton's Law of Cooling states that the rate at which and objects cools is directly proportional to the difference in temperature between the object an the surrounding medium. if an object cools from 125F to 100F in half an hour when surrounded by air at a temperautre of 75F, find it's temperature at the end of the next half hour. (Hint: we wrote a differenial equation involving a proportional relationship before in lecture)

Two identical small insulating balls are suspended by separate 0.293 m threads that are attached to a common point on the ceiling. Each ball has a mass of 7.96E-4 kg. Initially the balls are uncharged and hang straight down. They are then given identical positive charges and, as a result, spread apart with an angle of 34.6 ° between the threads. Determine the charge on each ball.