One end of a cord is fixed and a small 0.550-kg object is attached to the other end, where it swings in a section of a vertical circle of radius 3.00 m, as shown in the figure below. When θ = 17.0°, the speed of the object is 9.00 m/s. An object is swinging to the right and upward from the end of a cord attached to a horizontal surface. The cord makes an angle θ with the vertical. An arrow labeled vector v points in the direction of motion.

(a) At this instant, find the magnitude of the tension in the string. ____N

(b) At this instant, find the tangential and radial components of acceleration. at = _____m/s2 inward ac = ____m/s2 downward tangent to the circle

(c) At this instant, find the total acceleration. ___ inward and below the cord at °_____

A 200 micro Farad capacitor is charged up by connecting it in series with a 10,000 ohm resistor and a 25 V
battery. What is the maximum amount of charge that can be stored on the capacitor in mC?

Ch.8, 4

The tires of a car make 72 revolutions as the car reduces its speed uniformly from 88.0 km/h to 60.0 km/h. The tires have a diameter of 0.82 m.

Part A

What was the angular acceleration of the tires?

Part B

If the car continues to decelerate at this rate, how much more time is required for it to stop?

Part C

If the car continues to decelerate at this rate, how far does it go? Find the total distance.

A car of mass 500 kg is going towards east at 20.0 m/s. It hits a slow moving truck (moving at speed 10.0 m/s also going towards east) of mass 2000 kg from back. (a) If after the collision the truck is moving at 15.0 m/s towards east, what is the velocity of the car? (b) If the collision between the car and the truck is perfectly elastic, find their velocities after the collision. (c) Find the percentage loss of kinetic energy of the vehicles due to the collision in both cases.

Consider two identical uniform bricks each of length "L" which are staggered and stacked in parallel with one on top of the other. Find the maximum possible overhang beyond the table's edge the system can have without toppling. Express your answer in terms of "L." Hint: apply the "free-standing body" theorem THREE TIMES.

Please show work

An L-R-C series circuit consists of a 2.40 μF capacitor, a 6.00 mH inductor, and a 60.0 Ω resistor connected across an ac source of voltage amplitude 10.0 V having variable frequency.

Part A: At what frequency is the average power delivered to the circuit equal to 1/2*V_rms*I_rms? (ω = ____rad/s)

Part B: Under the conditions of part (a), what is the average power delivered to each circuit element? (P_R, P_C, P_L = ____W)

Part C: What is the maximum current through the capacitor? (I_C = ____A)

A projectile is fired at ?0=394.0 m/s at an angle of ?=68.1∘ , with respect to the horizontal. Assume that air friction will shorten the range by 34.1% . How far will the projectile travel in the horizontal direction, ? ?

The question I have to solve is that when two people A and B run in the opposite direction at the same speed 0.6c, do they agree with the referee that says the result is draw.
I want to approach this question in a different way so I set that A looks back to B when he runs to the goal and feels like B is running at 0.88c. Then does A think B is slower than A because the relative speed is 0.88c-0.6c=0.22c? Or am I wrong to think this way? I already found other methods such as time dilation so please focus on the first method. Thank you.

A flat sheet of chrystalline quartz has a thickness of 2.48 cm. It is on top of a flat sheet of fused quartz that has a thickness of 1.50 cm. Light strikes the chrystalline quartz perpendicularly and travels through it and then through the fused quartz. In the time it takes the light to travel through the two sheets, how far (in cm) would it have traveled in a vacuum?

1.You measure the velocity of an electron to an accuracy of ±22.6 m/s. What is the minimum uncertainty in its position? (h = 6.626 × 10-34 J ∙ s, melectron = 9.11 × 10-31 kg)

A 32.2 μm

B4.03 μm

C5.12 µm

D 8.05 μm

E16.1 μm

2.A 10-g bouncy ball is confined in a 8.3-cm-long box. What is its minimum energy? (h = 6.626 × 10-34 J ∙ s)

A.8.1 × 10-65 J

B.9.4 × 10-75 J

C.3.2 × 10-46 J

D.1.3 × 10-20 J

I am doing an experiment recording the speed of sound. I am using an open-ended cardboard tube that is 76.2cm (30") and the temperature in my room is 75 degrees or 23.89 celsius.

What is my speed of sound (using the speed of sound expression with explanation please)?

Given the length of my tube, what are my first five wavelengths that my tube should resonate (using the standing sound wave formula)?

What are my five wavenumbers (k) of the above (reciprocal).

What should  my first five resonance frequencies (predicted) be? If i understand this correctly, I do this using the theoretical speed of sound calculated above together with the five resonance wavelengths also determined above.

The average thermal energy of a particle is ~ k_BT where k_B is Boltzmann’s constant and T is the temperature in degrees Kelvin. At room temperature, k_BT = 25 meV = 4.1 x 10-21 J = 4.1 pN – nm =0.6 kcal/mole (eV = electron volts; J = Joules, N = Newtons; kcal = kilocalories).

a. A typical molecular motor uses 100 to 1000 ATP molecules per second. Calculate how much energy is dissipated in the motor (in Watts, or J/s). Call this power quantity M.

b. Nuclear vibrations occur on the time scale of 10^-13 sec. Compute the scale of power input to a molecular motor from random collisions with surrounding water and call it R, assuming that the collisions transfer about k_BT of energy each. Estimate the ratio R/M.

c. How does your estimate differ if you assume that water molecules require a diffusion time given by Δx²/D to transfer k_BT of energy to the motor, where Δx is the average distance between water molecules in solution?

“High voltage” power lines are often seen suspended high above the ground. Two of these power lines are suspended above a physics professor who is out for a walk. The power line on the left carries a current out of the page; the power line on the right carries a current into the page.

a) What is the direction of the magnetic field produced by the two currents at the location of the physics professor? He is on the ground halfway between the two wires. Draw a diagram illustrating your reasoning. Hint: Determine the direction of the magnetic field produced by each current separately, then add them together.

b) The physics professor has been shuffling his feet on the ground as he walks to the right which has made him become negatively charged. Determine the direction of the magnetic force (if any) exerted by the magnetic field on him. Explain your reasoning.

c) Does the power line on the left exert a force on the power line on the right? Explain your reasoning. If you think it does, determine its direction.

An ambulance traveling eastbound at 144.0 km/h with sirens blaring at a frequency of 7.50 ✕ 10² Hz passes cars traveling in both the eastbound and westbound directions at53.0 km/h. (Assume the speed of sound is 343 m/s.)

(a) What is the frequency observed by the eastbound drivers as the ambulance approaches from behind?
_______Hz

(b) What is the frequency observed by the eastbound drivers after the ambulance passes them?
_______Hz

(c) What is the frequency observed by the westbound drivers as the ambulance approaches them?
________ Hz

(d) What is the frequency observed by the westbound drivers after the ambulance passes them?
_________ Hz

A high-energy photon in the vicinity of a nucleus can create an electron-positron pair by pair production:

γ → e⁻ + e⁺.

(1) What minimum energy photon is required?
_____________MeV

(2) Why is the nucleus needed?

a)Electrons can only exist inside the nucleus. b)Positrons can only exist inside the nucleus. c)The nucleus is required to absorb the energy so that conservation of energy is not violated. d)The nucleus is required to absorb the momentum so that conservation of momentum is not violated.