A mysterious tower has been constructed at the edge of a gridiron football field. Even more mysteriously, the field has been marked carefully in meters instead of yards. On top of the tower is a well calibrate ball launcher that will fire heavy ball at a velocity of 14.7 m/s at an angle of 20 degrees abive the horizontal. The ball lands 46.1 meters away from the base of the tower.

A) How long does it take for the ball to reach max height?

B)How long does it take for the ball to return to the height from which it was launched?

C) What is the total flight time of the ball?

D) How tall is the tower?

Please explain the contiguity of spacetime?

A magnetic field is along the xy plane and the z plane is perpendicular to the magnetic field. In which plane(s) is the magnetic flux the greatest? Please explain.

At t = 0s, the leading edge of a wave (wavelength 1m) is 3m to the left of a boundary. The wave is moving to the right at 1m/s. The transmitted wave has wavelength 3m. (You may draw pictures to help you answer the questions below, but you must explicitly state - in words - the answers to the questions.)

(a)[8 pt(s) ]At t = 5s, where is the leading edge of the transmitted wave? Is the transmitted wave inverted or non-inverted, and why?

A 16.5-μμF capacitor is charged to a potential of 60.0 V and then discharged through a 75.0­ ΩΩ resistor.

1)

How long after discharge begins does it take for the capacitor to lose 90.0% of its initial charge? (Express your answer to three significant figures.)

answer .....ms

How long after discharge begins does it take for the capacitor to lose 90.0% of its initial energy? (Express your answer to three significant figures.)

answer .....ms

What is the current through the resistor at the time when the capacitor has lost 90.0% of its initial charge? (Express your answer to three significant figures.)

answer .....mA

What is the current through the resistor at the time when the capacitor has lost 90.0% of its initial energy? (Express your answer to three significant figures.)

answer ....mA

Projectile Motion 2D

A batter hits a ball with initial speed 20m/s at a launch angle of 60

A hollow, thin-walled sphere of mass 11.0 kg and diameter 48.0 cm is rotating about an axle through its center. The angle (in radians) through which it turns as a function of time (in seconds) is given by θ(t)=At2+Bt4, where A has numerical value 1.20 and Bhas numerical value 1.60.

At the time 3.00 s , find the angular momentum of the sphere.

At the time 3.00 s , find the net torque on the sphere.

Most of us know intuitively that in a head-on collision between a large dump truck and a subcompact car, you are better off being in the truck than in the car. Why is this? Many people imagine that the collision force exerted on the car is much greater than that exerted on the truck. To substantiate this view, they point out that the car is crushed, whereas the truck is only dented. This idea of unequal forces, of course, is false; Newton's third law tells us that both objects are acted upon by forces of the same magnitude. The truck suffers less damage because it is made of stronger metal. But what about the two drivers? Do they experience the same forces? To answer this question, suppose that each vehicle is initially moving at 6.40 m/s and that they undergo a perfectly inelastic head-on collision. Each driver has mass 72.0 kg. Including the masses of the drivers, the total masses of the vehicles are 800 kg for the car and 4,000 kg for the truck. If the collision time is 0.100 s, what force does the seat belt exert on each driver? force on truck driver N force on car driver N

A large boulder is ejected vertically upward from a volcano with an initial speed of 40.7 m/s . Air resistance may be ignored. A) At what time after being ejected is the boulder moving at a speed 20.3 m/s upward? B) At what time is it moving at a speed 20.3 m/s downward? C)When is the displacement of the boulder from its initial position zero? D)When is the velocity of the boulder zero? E)What is the magnitude of the acceleration while the boulder is moving? F)What is the direction of the acceleration while the boulder is moving? (up or down)

Throw a ball so that it is projected vertically upward. Catch it at the same height it was released. Have a partner measure the time the ball is in the air - that is, from the time of release to the time the ball lands in your hand.

Throw a ball so that it is projected vertically upward. Catch it at the same height it was released. Have a partner measure the time the ball is in the air - that is, from the time of release to the time the ball lands in your hand.
Determine the velocity of the ball at the moment of release and the distance the ball traveled before it started its descent. Graph the flight of the ball into five sections: (1) from initiation of upward motion of the hand to just prior to release, (2) from moment of release to just before maximum height, (3) at maximum height, (4) from maximum height to just before you catch the ball, (5) from the ball contact to the ball being brought to rest. For each section, describe the displacement, velocity, and acceleration.

Determine the velocity of the ball at the moment of release and the distance the ball traveled before it started its descent. Graph the flight of the ball into five sections: (1) from initiation of upward motion of the hand to just prior to release, (2) from moment of release to just before maximum height, (3) at maximum height, (4) from maximum height to just before you catch the ball, (5) from the ball contact to the ball being brought to rest. For each section, describe the displacement, velocity, and acceleration.

A point particle with charge

q = 4.2 ?C

is placed on the x axis at

x = ?10 cm

and a second particle of charge

Q = 7.8 ?C

is placed on the x axis at

x = +25 cm.

(a) Determine the x and y components of the electric field due to this arrangement of charges at the point

(x, y) = (10, 10)

(the units here are centimeters).

(b) Determine the magnitude and direction of the electric field at this point.

1. A train moving at a constant speed of 52.0 km/h moves east for 38.0 min, then in a direction 45.0° east of due north for 21.0 min, and then west for 65.0 min. What is the average velocity of the train during this run? a) magnitude- km/h b) ° (counterclockwise from east) 2. A golf ball is struck at ground level. The speed of the golf ball as a function of time is shown in the figure below, where t = 0 at the instant the ball is struck. The graph is marked in increments of 0.25 s along the time axis, and vmin = 18.60 m/s and vmax = 22.27 m/s. (Values in figure do not necessarily match values in problem). a) How far does the golf ball travel horizontally before returning to ground level? b) What is the maximum height above the ground level attained by the ball? 3. A projectile's launch speed is 3.1 times its speed at maximum height. Find launch angle ?0. 4. In the figure, a ball is thrown leftward from the left edge of the roof, at height h above the ground. The ball hits the ground 1.37 s. later, at distance d = 20.5 m from the building and at angle ? = 56° with the horizontal. a) Find h= m b) What is the velocity at which the ball is thrown? Magnitude= m/s Angle= ° relative to the horizontal c) Is that angle above or below the horizontal? Above/below

A film of oil lies on wet pavement. The refractive index of the oil exceeds that of the water. The film has the minimum nonzero thickness such that it appears dark due to destructive interference when viewed in red light (wavelength = 640.0 nm in vacuum). Assuming that the visible spectrum extends from 380 to 750 nm, for which visible wavelength(s) in vacuum will the film appear bright due to constructive interference?

The great russian physicist Lev Landau developed a famous entry exam to test his students. This "Theoretical Minimum" contained everything he considered elementary for a young theoretical physicist. Despite its name, it was notoriously hard and comprehensive, and in Landau's time, only 43 students passed it.

I wonder if anyone can provide the list of topics, or even a copy of the exam?

(I'm sure I'd have no chance to pass, but I'd like to see it out of a sense of sportmanship ;-). Also, I think it would make quite a good curriculum of theoretical physics (at least pre 1960).)

What type of motion is occurring when the slope of a velocity vs. time graph is zero? Also, what type of motion is occurring when it's not zero