A textbook of mass 2.06 kg rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.100 m , to a hanging book with mass 2.99 kg . The system is released from rest, and the books are observed to move a distance 1.24 m over a time interval of 0.750 s.
a) What is the tension in the part of the cord attached to the textbook?
b) What is the tension in the part of the cord attached to the book? (Take the free fall acceleration to be g = 9.80 m/s2.)
c) What is the moment of inertia of the pulley about its rotation axis? (Take the free fall acceleration to be g = 9.80 m/s2.)
In: Physics
You accidentally drop an eraser out the window of an apartment 17 m above the ground.
Part A:
How long will it take for the eraser to reach the ground?
Express your answer to three significant figures and include the appropriate units.
Part B:
What speed will it have just before it reaches the ground?
Express your answer to three significant figures and include the appropriate units.
Part C:
. If you multiply the time interval answer from a and the speed answer from b, why is the result much more than 15 m?
In: Physics
A uniform ladder of length L and mass m leans against a frictionless vertical wall, making an angle of 55° with the horizontal. The coefficient of static friction between the ladder and the ground is 0.40. If your mass is four times that of the ladder, how high can you climb before the ladder begins to slip?
In: Physics
Very large magnetic fields can be produced using a procedure called flux compression. A metallic cylindrical tube of radius R is placed coaxially in a long solonoid of somewhat larger radius. The space between the tube and the solonoid is filled with a highly explosive material. When the explosive is set off, it collapses the tube to a cylinder of radius r<R. If the collapse happens very rapidly, induced current in the tube maintains the magnetic flux nearly constant inside the tube. If the initial magnetic field in the solonoid is T and R/r=12.0, what maximum value of magnetic field can be achieved?
In: Physics
At t = 0, a flywheel has an angular velocity of 6.2 rad/s, an angular acceleration of -0.18 rad/s2, and a reference line at θ0 = 0. (a) Through what maximum angle θmax will the reference line turn in the positive direction? What are the (b) first and (c) second times the reference line will be at θ = θmax/5? At what (d) negative time and (e) positive time will the reference line be at θ = -7.7 rad?
In: Physics
If the wavelength of a wave on a string is increased, will you see more nodes or fewer nodes? Explain.
In: Physics
Describe how the electrons in Rutherford's atom must have behaved, and explain why this model could not have been possible.
In: Physics
The angular position of a point on the rim of a rotating wheel is given by θ = 9.33t - 3.93t2 + 1.09t3, where θ is in radians and t is in seconds. What are the angular velocities at (a) t = 2.13 s and (b) t = 8.41 s? (c) What is the average angular acceleration for the time interval that begins at t = 2.13 s and ends at t = 8.41 s? What are the instantaneous angular accelerations at (d) the beginning and (e) the end of this time interval?
In: Physics
A beetle with a mass of 25.0 g is initially at rest on the outer edge of a horizontal turntable that is also initially at rest. The turntable, which is free to rotate with no friction about an axis through its center, has a mass of 80.0 g and can be treated as a uniform disk. The beetle then starts to walk around the edge of the turntable, traveling at an angular velocity of 0.0700 rad/s clockwise with respect to the turntable. (b) With respect to you, motionless as you watch the beetle and turntable, what is the angular velocity of the beetle? Use a positive sign if the answer is clockwise, and a negative sign if the answer is counter-clockwise. rad/s (c) What is the angular velocity of the turntable (with respect to you)? Use a positive sign if the answer is clockwise, and a negative sign if the answer is counter-clockwise. rad/s (d) If a mark is placed on the turntable at the beetle's starting point, how long does it take the beetle to reach the mark again?
In: Physics
In: Physics
Please answer these 3 questions...thank you!
In: Physics
calculate the work done when: a) a 55 N force acting at an angle of 28 degrees to the horizontal pushes an object 5m horizontally. b) a spring of spring constant 45n/m is stretched by 32cm.
In: Physics
6-Torque on a coil. A circular loop of wire has a diameter of
20.0 cm and contains 10 loops. The current
in each loop is 3.00 A, and the coil is placed in a 2.00-T external
magnetic field. Determine the maximum
and minimum
torque exerted on the coil by the field.
In: Physics
Your employer asks you to build a 23-cm-long solenoid with an interior field of 6.0 mT . The specifications call for a single layer of wire, wound with the coils as close together as possible. You have two spools of wire available. Wire with a #18 gauge has a diameter of 1.02 mm and has a maximum current rating of 6 A. Wire with a #26 gauge is 0.41 mm in diameter and can carry up to 1 A.
A) Which wire should you use?
B) What current will you need?
In: Physics