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You are working in your dream job: an assistant for the special effects department of a movie studio. You have just been given this assignment: the star of a horror movie is walking down a spooky hallway when suddenly, due to some unknown and strange supernatural forces, all the pictures hanging on the wall start rotating about their upper edges until they are sticking straight out from the wall! To set up this effect, you attach the pictures to the wall with hinges along their upper end and wrap 20 turns of wire around the outside frame of the picture, as shown in Figure P28.32a. You set up a uniform magnetic field in the hallway that is directed upward and oriented at an angle of γ = 5.00° to the vertical, with its horizontal component directed perpendicularly into the wall. When you send a current of I = 10.0 A through the wire around each picture, the frame swings up perpendicular to the wall as shown in Figure P28.32b. Consider a particular picture of width ω = 40.6 cm, height h = 50.8 cm, and mass m = 0.750 kg. (a) Your supervisor asks you to determine the magnetic field magnitude that is necessary for this picture to rotate so that its face is parallel to the floor and perpendicular to the wall, as in Figure P28.32b. (b) She also asks about any dangers associated with this magnetic field.
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Chapter 28 Solutions
PHYSICS F/ SCIENTISTS&ENGINEERS(LL)W/AC
- Given the following equations of motion, and matrix P, 6.0000 0.0000 90.0000 -44.0000 |{x(t)}+ {x(t)}= 0, 0.6256 0.7802 [P]= 0.7802 -0.6256 0.0000 4.0000 -44.0000 44.0000 Determine the modal matrix [S]. 0.8580 0.6256 [S]= -0.5137 0.7802 0.7802 -0.6325 [S]= -0.6256 0.7746 0.2554 0.3185 [S]= 0.3901 -0.3128 0.8580 -0.6325 [S)= -0.5137 0.7746 Nonearrow_forward1. A student runs to school, covering a distance of 0.50 km in a direction of [N20^0 E] as measured from the starting point. She then trudges over to a friend's house 0.30 km away [W] from the school. The two friends then go off to the mall that is 0.8 km [W50^0S] from the friend's house. *You will need to draw the x and y components of the vectors a. What is the total displacement of the student? b. If the total time taken by the student to run to school then trudge over to the friend's house was 25 minutes, what was her average velocity? *There are many steps to this answer, ensure that you have included ALL steps.arrow_forwardLw21a.pdf bad p111w21a.pdf (113 KB) 7). A particle is moving in three dimensions. Its position vector r is given by r[t] = -4 I + (6 - 7 t) j +(1 – 3 t + 2t²) k where distance components are in meters and time t is in seconds. 7a) What are all 3 components of the velocity vector at t = +5 seconds? 7b) What are all 3 components of the acceleration vector at t = +5 seconds?arrow_forward
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- These two questions are very similar. However, when I was working through them and also looking at the textbook answers, question 32 includes V0 in the formula (x-x0)=V0t+1/2at^2. However, in questions 36 V0 is 0. If this is the case why isn't V0=0 in question 32. I'm referring to part A in both questions. I am confused! please help!arrow_forwardA string with a 10-gram decoration on the end is attached to the rear-view mirror of your friend’s father’s Ferrari. You’re curious about how fast this fancy sports car can accelerate. You decide to measure the acceleration by measuring the angle that the string makes with the vertical when the car is accelerating. Your friend’s father puts the pedal to the metal. Using a protractor, you measure that the angle the string makes with the vertical is 40 while the car is accelerating. What is the acceleration of the Ferrari? [Hints: Choose the decoration as the system for your force diagram. Use the vertical-component equation of Newton’s second law to find the magnitude of the force that the string exerts on the decoration. Then continue with the horizontal-component equation.]arrow_forwardThe Earth is 8 light minutes from the sun and the speed of light is 3 x 10° m.s. Let's assume that earth's orbit is exactly circular. Its mass is 5.972 × 1024 kg. Using the values given above (and your knowledge about time units), determine the magnitude of the gravitational force that the Sun exerts on the Earth. The magnitude of the force is newtons. Format: if your answer is 2 × 10° N, enter 2*10^3 (and do think about significant figures)arrow_forward
- Suppose that, while lying on a beach near the equator watching the Sun set over a calm ocean, you start a stopwatch just as the top of the Sun disappears. You then stand, elevating your eyes by a height H = 1.70 m, and stop the watch when the top of the Sun again disappears. If the elapsed time is t = 11.1 s, what is the radius r of Earth?arrow_forward5. Given: Three forces act on particle P. Force A has a magnitude of 15 N and acts 60° CCW from the positive x-axis. Force B has a magnitude of 60 N and acts along a ray from point P with a slope of -4/3. Force C has a magnitude of 10 N and acts straight left (180° CCW from positive x- axis). Find the Vector Sum: a. Draw a neat, labeled, scaled diagram representing the tip-to-tail vector addition R=A+B+C. Rx = 15cos60+60(3/5) — 10 and Ry = 15sin60-60(4/5) b. Add the three vectors to find the scalar components of the resultant, Rx and Ry. C. Find the magnitude of the resultant R and the angle 0 it makes with the positive x-axis.arrow_forwardA vector of 6 units makes an angle of 45 degrees with the positive x-axis. His vehicles are X-rays and Z-Zs Ax = 3.57 Ay = -4 0 %3D %3D Ax = 2.78 Ay = -7 0 %3D Ax = 2.53 Ay = 2 Ax = 4.24 Ay = 4.24 %3D %3Darrow_forward
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