At takeoff a commercial jet has a 70.0 m/s speed. Its tires have a diameter of 0.400 m.

(a) At how many rpm are the tires rotating?
  rpm
(b) What is the centripetal acceleration at the edge of the tire?
  m/s²
(c) With what force must a determined 10^-15 kg bacterium cling to the rim?
N
(d) Take the ratio of this force to the bacterium's weight.
(force from part (c) / bacterium's weight)

(a) A 23.0 kg child is riding a playground merry-go-round that is rotating at 45.0 rpm. What centripetal force must she exert to stay on if she is 2.50 m from its center?
  N
(b) What centripetal force does she need to stay on an amusement park merry-go-round that rotates at 3.00 rpm if she is 5.00 m from its center?
  N
(c) Compare each force with her weight.
  (force from part (a) / weight)
  (force from part (b) / weight)

All of these answers wrong someone please help me.

Special relativity

Q: What is Einstein’s special relativity principle?

Q: What is the relativity of simultaneity?

Q: What is time dilation? Length contraction?

Q: Why is there a cosmic speed limit?

A skeet shooter aims at a clay pigeon. The muzzle velocity of the rifle is 700 mph and the man holds the rifle such that the end of the gun is 6 ft off the ground. Assuming that the speed of the skeet is insignificant relative to the speed of the bullet, determine the angle at which the man needs to hold the rifle in order to hit a clay pigeon that is 50 yards away and at an altitude of 30 ft.

How long will it take to form a thickness of 10 cm of ice on the surface of a lake when the air temperature is -15°C? The thermal conductivity K of ice is 4 x 10^-3 cal/s*cm*°C and its density is 0.92 g/cm^3

1. A 7130-kg car is travelling at 24.8 m/s when the driver decides to exit the freeway by going up a ramp. After coasting 418 m along the exit ramp the car\'s speed is 12.4 m/s, and it is h = 12.5 m above the freeway. What is the magnitude of the average drag force exerted on the car?

2. The superheroine Xanaxa, with a mass of 66.3 kg, is in a hair-raising chase after the 74.3-kg arch-villain Lexlax. She leaps from the ground to the top of a 195-m-high building, then dives off and comes to rest at the bottom of a 16.7-m-deep excavation, where she finds Lexlax and neutralizes him. Does all this bring about a net gain or a net loss of gravitational potential energy? Loss or Gain

By how much? Answer with a positive number. Take g = 9.81 m/s2.

3.Tom has built a large slingshot, but it is not working quite right. He thinks he can model the slingshot like an ideal spring, with a spring constant of 75.0 N/m. When he pulls the slingshot back 0.305 m from a non-stretched position, it just doesn\'t launch its payload as far as he wants. His physics professor \"helps\" by telling him to aim for an elastic potential energy of 14.5 Joules. Tom decides he just needs elastic bands with a higher spring constant. By what factor does Tom need to increase the spring constant to hit his potential energy goal?

During a followup conversation, Tom\'s physics professor suggests that he should leave the slingshot alone and try pulling the slingshot back further without changing the spring constant. How many times further than before must Tom pull the slingshot back to hit the potential energy goal with the original spring constant?

4. An adult dolphin weighs around 1610 N. How fast must he be moving as he leaves the water vertically in order to jump to a height of 3.50 m? Ignore air resistance.

5. Nate the Skate was an avid physics student whose main non-physics interest in life was high-speed skateboarding. In particular, Nate would often don a protective suit of Bounce-Tex, which he invented, and after working up a high speed on his skateboard, would collide with some object. In this way, he got a gut feel for the physical properties of collisions and succeeded in combining his two passions.* On one occasion, the Skate, with a mass of 119 kg, including his armor, hurled himself against a 801-kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.37 m/s and Nate bounced backward. What were Nate\'s speeds immediately before and after the collision? (Enter positive numbers.) Ignore friction with the ground. Before:_______m/s, After:_______m/s

*By the way, this brief bio of Nate the Skate is written in the past tense, because not long ago he forgot to put on his Bounce-Tex before colliding with the Washington Monument in a perfectly inelastic collision. We will miss him.

Two speakers are facing each other, 4.00 meters apart, in phase and playing a sound with frequency 170HZ. Find the distance from the center point to the nearest point where totally destructive interference occurs.

A 4.00-kg block rests on an inclined plane that has an inclination angle of 31.3o. A string attached to this block, goes uphill and over a frictionless pulley, and then is attached to a hanging block of mass M. The inclined plane has coefficients of friction μs = 0.22 and μk = 0.13.

Draw a real world picture of this scenario.

Draw the free body diagrams for each of the blocks.

Show how to determine the mass M that will cause the blocks to start moving.

Once the blocks are moving, show how to determine the acceleration of the blocks.

Show how to determine the speed and distance that the blocks have moved after 5.55 seconds

(1 point) Suppose a pendulum with length L (meters) has angle θ (radians) from the vertical. It can be shown that θ as a function of time satisfies the differential equation:

((d^2)θ)/(dt^2))+(g/L)sinθ=0

where g=9.8/sec is the acceleration due to gravity. For small values of θ we can use the approximation sin(θ)∼θ, and with that substitution, the differential equation becomes linear.

A. Determine the equation of motion of a pendulum with length 0.5 meters and initial angle 0.5 radians and initial angular velocity dθ/dt 0.4 radians/sec.

B. At what time does the pendulum first reach its maximum angle from vertical? (You may want to use an inverse trig function in your answer)

seconds

C. What is the maximum angle (in radians) from vertical?

D. How long after reaching its maximum angle until the pendulum reaches maximum deflection in the other direction? (Hint: where is the next critical point?)

seconds

E. What is the period of the pendulum, that is the time for one swing back and forth?

seconds

Imagine that you have obtained spectra for several galaxies and have measured the observed wavelength of a hydrogen emission line that has a rest wavelength of 656.3 nanometers. Here are your results:

Galaxy 1: Observed wavelength of hydrogen line is 658.7 nanometers

Galaxy 2: Observed wavelength of hydrogen line is 664.2 nanometers.

Galaxy 3: Observed wavelength of hydrogen line is 683.6 nanometers.

Part D: Estimate the distance to each galaxy from Hubble's law. Assume that H0=22km/s/Mly.

Express your answers using two significant figures. Enter your answers numerically separated by commas.

(dgalaxy1, dgalaxy2, dgalaxy3 = *Answer* Mly)

Objects with masses of 165 kg and a 465 kg are separated by 0.390 m. (a) Find the net gravitational force exerted by these objects on a 41.0 kg object placed midway between them. magnitude? direction? (b) At what position (other than infinitely remote ones) can the 41.0 kg object be placed so as to experience a net force of zero?

Which of the following electron jumps in a hydrogen atom emits the photon of highest frequency?

a) n=2 to n=3
b) n=1 to n=2
3) n=3 to n=2
4) n=2 to n=1

A 0.50-?F and a 1.4-?F capacitor (C1 and C2, respectively) are connected in series to a 15-V battery.

Part A. Calculate the potential difference across each capacitor. Express your answers using two significant figures separated by a comma.

Part B. Calculate the charge on each capasitor. Express your answers using two significant figures separated by a comma.

Part C. Calculate the potential difference across each capacitor assuming the two capacitors are in parallel. Express your answers using two significant figures separated by a comma.

Part D. Calculate the charge on each capasitor assuming the two capacitors are in parallel. Express your answers using two significant figures separated by a comma.

Polarized light is to have its polarization plane rotated by 90 degrees. In which of the following cases does the final beam have the greatest intensity?

Select one:

a. 1 polarizing filter, rotating the beam by 90 degrees

b. 3 polarizing filters, both rotate the beam by 30 degrees

c. 6 polarizing filters, each rotating the beam by 15 degrees

d. None of the above, polarized light can't be rotated

please explain the answer think it is C.

A flywheel with a diameter of 1.39 m is rotating at an angular speed of 194 rev/min. (a) What is the angular speed of the flywheel in radians per second? (b) What is the linear speed of a point on the rim of the flywheel? (c) What constant angular acceleration (in revolutions per minute-squared) will increase the wheel's angular speed to 1280 rev/min in 128 s? (d) How many revolutions does the wheel make during that 128 s?

5. a)Which component offers a measureable resistance to the circuit: Resistor or Capacitor?

b) Let's say you measure t_1/2 to be 0.3018 seconds and the resistance in the circuit is 68 Ohms. Then what is the capacitance in micro Farads?
answer in micro Farads.

c) t_1/2 means that the voltage (or charge) of the system will increase to half more of what is left in a time equal to t_1/2 seconds.
Therefore if a system is already at half charge (t_1/2 seconds after starting) then after t_1/2 more seconds the system will be charged to 50% plus half of 50%. That is 25% more, or 75% of the entire charge. Let's say that four t_1/2's have gone by. That means that the charge (or voltage) is at (50% + 1/2*50% + 1/2*1/2*50% + 1/2*1/2*1/2*50%) = 93.75% of maximum charge.
Yikes! Now look in your manual for a more simple mathematical derivation of this concept.

Given t_1/2 to be 0.9653 seconds, how long should it take to reach 75% of maximum charge?
answer in seconds.