A wheel, starting from rest, has a constant angular acceleration of 0.7 rad/s^2. In a 0.5-s interval, it turns through an angle of 101 rad. How long has the wheel been in motion at the start of this 0.5-s interval?

An ancient club is found that contains 180 g of pure carbon and has an activity of 5.5 decays per second. Determine its age assuming that in living trees the ratio of (14C12C)(14C12C) atoms is about 1.40×10−121.40×10−12. Note that the half life of carbon-14 is 5700 years and the Avogadro number is 6.02×10236.02×1023.

11. Can a 12 cm telescope distinguish two stars that are 1.5 arcseconds away from each other? Justify your answer numerically. (You can assume we're using light in the middle of the visual band.)

A rigid tank contains 71.0 g of chlorine gas (Cl2) at a temperature of 70°C and an absolute pressure of 5.20 × 105 Pa. Later, the temperature of the tank has dropped to 37°C and, due to a leak, the pressure has dropped to 3.50 × 105 Pa. How many grams of chlorine gas have leaked out of the tank? (The mass per mole of Cl2 is 70.9 g/mol.)

A 14.7 μF capacitor is charged to a potential of 55.0 V and then discharged through a 75.0 Ω resistor.

(a) How long after discharge begins does it take for the capacitor to lose 90.0% of the following?

(i) its initial charge: _______s

(ii) its initial energy: _______s

(b) What is the current through the resistor at both times in part (a)?

(i) at t_{charge: ________}A

(ii) at t_{energy: ________}A

(a) Compute the impedance of a series R-L-C circuit at angular frequencies of w1 = 1000 rad/s, w2 = 735 rad/s and w3 = 540 rad/s. Take =160 ohm, = 0.940 H and = 2.05 uF.

(b) Describe how the current amplitude varies as the angular frequency of the source is slowly reduced from 1000 to 540 .
a-Amplitude is always constant.
b-Amplitude decreases.
c-Amplitude increases.
d-First amplitude increases next it decreases.
e-First amplitude decreases next it increases.

(c) What is the phase angle of the source voltage with respect to the current when w = 1000 rad/s?

A passenger on a moving train walks at a speed of 1.40 m/s due north relative to the train. The passenger's speed with respect to the ground is 4.5 m/s at an angle of 30.0° west of north. What are the magnitude and direction of the velocity of the train relative to the ground?

A point charge +q is at the origin. A spherical Gaussian surface centered at the origin encloses +q. So does a cubical surface centered at the origin and with edges parallel to the axes. Select "True" or "False" for each statement below.

1. Suppose (for this statement only), that q is moved from the origin but is still within both the surfaces. The flux through both surfaces is changed.

2.If the radius of the spherical Gaussian Surface is varied, the flux through it also varies.

3. The area vector and the E-Field vector point in the same direction for all points on the spherical surface.

4. The E-Field at all points on the spherical surface is equal due to spherical symmetry.

5. The Electric Flux through the spherical surface is less than that through the cubical surface.

I tried :( F , T, F, T, F) but it is wrong, and I don't know which one is wrong.

I tried：

F T F T F

T F F T F

Both are wrong, and i dont know which one is wrong.

what is myopia and hyperopia? How can we correct these?

Two astronauts, Hans and Dexter, are on a spacewalk floating at rest next to their space vehicle. They argue and Hans shoots Dexter with a handgun. The bullet has a mass of 0.015 kg and a muzzle velocity of 250 m/s. Hans now finds himself drifting away from the spacecraft

a.) Hans and his spacesuit have a mass of 200 kg. how fast is he drifting away

b.) Hans only had one bullet, but he is holding a gun that has a mass of 1.1 kg. how fast must he throw it to stop drifting away from the spacecraft?

c.) Meanwhile, on earth, a solid cylinder of mass 5kg rolls without slipping toward a hill with a velocity of 5 m/s. how high up the hill will the cylinder roll?

The uncertainty principle arises from a common-sense idea: To measure something, you must affect it somehow. For instance, when you use a pressure gauge to measure air pressure in a car tire you release a small amount of air into the gauge.

• Why does shining very short wavelength photons on an electron not tell you exactly where the electron is?
• Describe two other examples of situations in which measuring something about an object somehow changes it.

An object is placed 68cm from a screen

1. At what point from the object should a converging lens with a focal length of 17cm be placed so that it will produce a sharp image on the screen? (in cm   from the object)

2. What is the image's magnification?

In this example we will apply the equations for constant angular acceleration to the simple case of a rotating bicycle wheel. The angular velocity of the rear wheel of a stationary exercise bike is ω0=4.00rad/s at time t=0, and its angular acceleration is constant and equal to α=2.45rad/s2. A particular spoke coincides with the +x axis at time t=0 (Figure 1). What angle does this spoke make with the +x axis at time t=3.00s? What is the wheel's angular velocity at this time? part A: How much longer will it take before the reference spoke is once again aligned with the +x axis? Part B: What will the angular speed of the wheel be at this time?

A small object is placed to the left of a convex lens and on its optical axis. The object is 50 cm from the lens, which has a focal length of 15 cm. Determine the location of the image formed by the lens. (Enter your answer in cm from the lens.)

_____ cm from the lens

Describe the image. (Select all that apply.)

real ____

Virtual ___

upright ____

Inverted ___

enlarged ___

Reduced ___

on the left side of the lens ___

on the right side of the lens __

A 64.7-kg skateboarder starts out with a speed of 2.44 m/s. He does 119 J of work on himself by pushing with his feet against the ground. In addition, friction does -257 J of work on him. In both cases, the forces doing the work are non-conservative. The final speed of the skateboarder is 7.88 m/s. (a) Calculate the change (PE_f - PE₀) in the gravitational potential energy. (b) How much has the vertical height of the skater changed? Give the absolute value.