At time t=0 a grinding wheel has an angular velocity of 29.0 rad/s . It has a constant angular acceleration of 29.0 rad/s² until a circuit breaker trips at time t = 2.30 s . From then on, the wheel turns through an angle of 433 rad as it coasts to a stop at constant angular deceleration.

A) Through what total angle did the wheel turn between t=0 and the time it stopped?

Express your answer in radians.

B) At what time does the wheel stop?

Express your answer in seconds.

C) What was the wheel's angular acceleration as it slowed down?

Express your answer in rad/s².

An object at rest explodes into three fragments. The figure shows the momentum vectors of two of the fragments:

• vector P1 is directed along the p_x axis and has a magnitude of 67.0 kg m/s.
• vector P2 is at an angle of 50.0° measured counterclockwise from the positive p_x axis and has a magnitude of 92.0 kg m/s.

What are the p_x and p_y components of the momentum of the third fragment?

Answer question 2!!

1. a boat is bobbing up and down on the water as waves pass underneath it. The depth of the water under the boat oscillates between 3 m and 4 m. The boat is stationary with respect to the shore and it is 2.9s between the crests of successive waves. A person on shore sees the crests of the wave passing by at 2 m/s. what is the distance between crests of this wave?

2. Two ducks are floating close together on the water near the boat in problem 1. When the first duck is on the peak of a passing wave the second duck is 30 cm below it and moving upwards. How far apart are the ducks?

Dario, a prep cook at an Italian restaurant, spins a salad spinner and observes that it rotates 20.0 times in 5.00 seconds and then stops spinning it. The salad spinner rotates 6.00 more times before it comes to rest. Assume that the spinner slows down with constant angular acceleration.

What is the magnitude of the angular acceleration of the salad spinner as it slows down?

Express your answer numerically in radians per second per second.

1

(a) How far from a 54.2 mm focal-length lens must an object be placed if its image is to be magnified 2.36? and be real?
_____ mm
(b) What if the image is to be virtual and magnified 2.36??
__________ mm

2

A diverging lens with a focal length of -14 cm is placed 14 cm to the right of a converging lens with a focal length of 18 cm. An object is placed 31 cm to the left of the converging lens.

(a) Where will the final image be located?
__________cm left of the converging lens
(b) Where will the image be if the diverging lens is 34 cm from the converging lens?
____________cm right of the diverging lens

A child slides down a hill on a toboggan with an acceleration of 1.5 m/s2.

Part A If she starts at rest, how far has she traveled in 1.0 s? Express your answer using two significant figures. dd = nothing m

Part B If she starts at rest, how far has she traveled in 2.0 s? Express your answer using two significant figures. dd = nothing m

Part C If she starts at rest, how far has she traveled in 3.0 s? Express your answer using two significant figures. dd = nothing m

A charge of -0.4 µC is located at the origin; a charge of 0.53 µC is located at x = 0.2 m, y = 0; a third charge Q is located at x = 0.32 m, y = 0. The force on the 0.53 µC charge is 4.3 N, directed in the positive x direction.

1. Determine the charge

2. With this configuration of three charges, where, along the x direction, is the electric field zero? xf=

3. x2=

Explain why it is difficult to make an X-ray laser.

What is the fastest transverse wave that can be sent along a given wire? For safety reasons, the maximum tensile stress to which this wire should be subjected is 3.56 × 108 N/m2. The density of the wire is 8300 kg/m3. Note that your answer does not depend on the diameter of the wire.

A 0.180-kg wooden rod is 1.60 m long and pivots at one end. It is held horizontally and then released.

Part A : What is the angular acceleration of the rod after it is released? Express your answer to three significant figures and include appropriate units.

Part B: What is the linear acceleration of a spot on the rod that is 0.560 m from the axis of rotation? Express your answer to three significant figures and include appropriate units.

Part C: At what location along the rod should a die be placed so that the die just begins to separate from the rod as it falls? Express your answer to three significant figures and include appropriate units.

At what radius along the perpendicular bisector of a wire of length 0.29 m carrying 30 nC of charge does the assumption of cylindrical symmetry in applying Gauss's law give you an answer whose error exceeds 5%?

Question1:playground merry-go-round has mass of 75kg and a radius of 3 m. A 25kg child sits on the merry-go-round 2/3's of way out from center.What's the moment of inertia of the merry-go-round/child system?

Question2:On the playground merry-go round in the previous question,one child pushes it CCW with a force of 20 N, while the 25 kg child drags her feet through a hole 2/3 of the way out from the center,causing a CW force of 17 N. What's angular acceleration of the merry-go-round?

Radiation from the head is a major source of heat loss from the human body. Model a head as a 21-cm-diameter, 20-cm-tall cylinder with a flat top.

If the body's surface temperature is 36?C , what is the net rate of heat loss on a chilly 9?C  day? All skin, regardless of color, is effectively black in the infrared where the radiation occurs, so use an emissivity of 0.95.

I have worked it through three times with other written solutions however i cannot arrive at the correct answer. A final answer as well as a solution would be appreciated! Thanks!

A- How much work is required to accelerate a proton from rest up to a speed of 0.995c?

W = ? J

B- What would be the momentum of this proton?

P = ? kg⋅m/s