On the way to lower floors, an elevator begins its descent from rest at a constant acceleration, ascending the first 0.5 m in 0.85s. What is the apparent weight of a 75 kg man inside the accelerator during this time interval?

.1 kn

.18 kn

.74 kn

.3 kn

Two charges are placed on the x-axis: one is placed at x = 3 m and the other is at x = -3 m. The magnitude of both charges is 5 µC but the blue one (at x = -3 m) is positive while the red one (at x = +3 m) is negative 1.What is the x-component of the electric field at (x, y) = (0 m, +4 m)? 3) Now the positive and negative charge switch places. The magnitude of the charges is still 5 µC where the blue one (now at x = +3 m) is positive and the red one (now at x = -3 m) is negative. What is the x-component of the electric field at (x, y) = (0 m, +4 m)? 4)Now both charges (still at x = -3 m and x = +3 m) are positive. The magnitude of the charges is still 5 µC. What is the y-component of the electric field at (x, y) = (0 m, +4 m)? 5)Finally, both charges (still at x = -3 m and x = +3 m) are negative. The magnitude of the charges is still 5 µC. What is the y-component of the electric field at (x, y) = (0 m, +4 m)?

Birds have evolved to the ability to control their motions through the air by controlling the forces exerted on their bodies by the air; the contact forces on a bird by the air plus the force of gravity on the bird by the Earth determine the change in motion of the bird at any instant of time. In this problem, you will be asked to use what you know about acceleration to track the motion of a diving hawk.

A hawk is flying horizontally Southward at an altitude of 165.0  m and at a speed of 2.10  m/s when he spots a slow-flying finch ahead of his current location and below his current path. At time zero, the hawk starts a dive by controlling the contact forces on him by the air so as to produce an acceleration of 5.30  m/s2 in a direction 69.0  degrees below horizontally Southward for a time of 1.250 seconds.

At the end of the 7.5-s interval, the hawk misses the finch and has to "put on the brakes". He does so by controlling the contact forces on him by the air so as to produce an acceleration of 4.651  m/s2 in a direction 70.104  degrees above horizontally Northward for a time of 1.5 seconds.

1. What is the hawk's final velocity at the end of the 1.5-s interval?

2.

Once again, please assume that the hawk's acceleration during the 1.5-s interval is constant. What is the hawk's displacement during the 1.5-s interval?

Give your answer as an ordered pair, with magnitude first, followed by a comma, then followed by the direction. Give the direction in terms of an angle measured below the horizontally Southward direction.

You have now been tracking the hawk's motion for a total of 1.250 + 7.5 + 1.5 = 10.25 seconds.

3. What is the total Southward displacement of the hawk during those 10.25 seconds? Specify the direction with a plus or minus sign assuming that Southward is positive and Northward is negative.

4. Finally, what is the final altitude of the hawk at the end of those 10.25 seconds?

A coin is moving in a horizontal circle in a cone. The cone has height 70 cm and radius 20 cm. The coin is at a height halfway up. The coefficient of static friction is 0.3. The mass of the coin is 5 g. How fast is the coin moving to stay at this height?If the velocity is halved what will the height of the coin be now?

A 0.41 μF and a 0.65 μF capacitor are connected in series to a 15 V battery.

Part A] Calculate the potential difference across each capacitor.

Part B] Calculate the charge on each capacitor.

Part C] Repeat part A assuming the two capacitors are in parallel.

Part D] Repeat part B assuming the two capacitors are in parallel.

briefly describe the procedure for the diffraction grating experiment

After being created in a high-energy particle accelerator, a pi meson at rest has an average lifetime of 2.60 10-8 s. Traveling at a speed very close to the speed of light, a pi meson travels a distance of 110 m before decaying. How fast is it moving? (Enter your answer to four significant figures.)

A cannon will launch balls at different angles but with the same inital velocity magnitude. If the cannon sits on the edge of a cliff that has a slope of 60 degrees, what is the distance along the slope of the ledge that the ball travels? If the inital velocity was 30 m/s and at which angle would the maximum distance be achieved?

A cylinder with a piston contains 0.200 mol of nitrogen at 1.70×10⁵ Pa and 320 K . The nitrogen may be treated as an ideal gas. The gas is first compressed isobarically to half its original volume. It then expands adiabatically back to its original volume, and finally it is heated isochorically to its original pressure.

Part A

Find the work done by the gas during the initial compression.

Correct

Part B

Find the heat added to the gas during the initial compression.

Correct

Part C

Find internal-energy change of the gas during the initial compression.

Correct

Part D

Find the work done by the gas during the adiabatic expansion.

Enter your answers numerically separated by commas.

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Part E

Find the heat added to the gas during the adiabatic expansion.

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Part F

Find the internal-energy change of the gas during the adiabatic expansion.

A lighter-than-air spherical balloon and its load of passengers and ballast are floating stationary above the earth. Ballast is weight (of negligible volume) that can be dropped overboard to make the balloon rise. The radius of this balloon is 4.47 m. Assuming a constant value of 1.29 kg/m3 for the density of air, determine how much weight must be dropped overboard to make the balloon rise 148 m in 13.0 s.

A toy gun uses a spring with a force constant of 350 N/m to propel a 15.0 g steel ball. The spring is compressed 8.40 cm and friction is negligible.

a) How much force (in N) is needed to compress the spring? (Assume the gun is aimed in the positive direction. Indicate the direction with the sign of your answer.)

b)To what maximum height (in m) can the ball be shot?

c)At what angles above the horizontal (in degrees) may a child aim to hit a target 3.00 m away at the same height as the gun? (Enter your answers to at least two decimal places.) smaller angle and larger angle?

* I already answered a and b: a) -29.4 N and b) 8.52 m, I just need C *

Steam at 100°C is added to ice at 0°C.

(a) Find the amount of ice melted and the final temperature when the mass of steam is 11.0 g and the mass of ice is 48.0 g.


(b) Repeat this calculation, when the mass of steam as 1.10 g and the mass of ice is 48.0 g.

A particle with a charge of 34 μC moves with a speed of 73 m/s in the positive x direction. The magnetic field in this region of space has a component of 0.42 T in the positive ydirection, and a component of 0.83 T in the positive zdirection.

Part A

What is the magnitude of the magnetic force on the particle?

Express your answer using two significant figures.

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Part B

What is the direction of the magnetic force on the particle? (Find the angle measured from the positive z-axis toward the negative y-axis in the yz-plane.)

Express your answer using two significant figures.

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A rock has mass 1.80 kg. When the rock is suspended from the lower end of a string and totally immersed in water, the tension in the string is 12.6 N .

What is the smallest density of a liquid in which the rock will float?

Express your answer with the appropriate units.