Case 1: A DJ starts up her phonograph player. The turntable accelerates uniformly from rest, and takes t1 = 11.6 seconds to get up to its full speed of f1 = 78 revolutions per minute. Case 2: The DJ then changes the speed of the turntable from f1 = 78 to f2 = 120 revolutions per minute. She notices that the turntable rotates exactly n2= 12 times while accelerating uniformly. t1 = 11.6 seconds n2 = 12 times a. Calculate the angular speed described in Case 1, given as f1 = 78 revolutions per minute, into units of radians/second. b. How many revolutions does the turntable make while accelerating in Case 1? c. Calculate the magnitude of the angular acceleration of the turntable in Case 1, in radians/second2. d. Calculate the magnitude of the angular acceleration of the turntable (in radians/second2) while increasing to 120 RPM (Case 2).

Two people swing jump ropes, as shown in the diagram. The highest point of the middle of each rope is M = 77 inches above the ground, and the lowest point is m 7 inches. The rope makes 4 revolutions per second. Write a model for the height h (in inches) of a rope as a function of the time t (in seconds) given that the rope is at its lowest point when t = 0. i ↑ h = h(t) = M Kit m -

A small child is learning to ride a bike for the first time. Her dad decides it would be a good idea to start her on a small hill. The hill is inclined at 3.40° to the horizontal. The child starts partway down the hill, 4.00 m away from her dad, who stays at the top. She starts to wobble, so her dad sprints toward her from rest with an acceleration of 3.80 m/s2. How far has the child gone before her parent catches her?

You and a friend ride your bikes to a restaurant across town. Both of you start at the same instant from your house, you riding 10 m/s and your friend riding 12 m/s. During the trip your friend has a flat tire and that takes him 8 minutes to fix. He then continues the trip at the same speed of 12 m/s. If the distance to the restaurant is 10 km, who gets there first?

An object moves in a circle of radius R at constant speed with a period T. By what factor should the period be changed so that the object's final acceleration magnitude is k times its initial value (that is, af = ka) where k = 0.53. Tf= = T

The figure below shows an object initially at point A traveling in the +x-direction. It turns in a circular path at constant speed until it is traveling in the +y-direction at point C. The quarter-circle arc from A to C is 245 m in length, and the particle moves from A to C in 38.0 s. Point B on the path is 35.0° below the x-axis. 0 35.0⁰ (a) What is the speed of the object (in m/s)? m/s Need Help? (b) What is the magnitude and direction of the acceleration when the object is at point B? (Enter the magnitude in m/s² and the direction in degrees counterclockwise from the +x-axis.) magnitude m/s² direction Read It counterclockwise from the +x-axis

Problem 1: While sitting in physics class one day, you begin to ponder the workings of the analog clock on the classroom wall. You notice as the hands sweep in a continuous motion that there are exactly t = 35 minutes left in class. 11 10 Randomized Variables 3 t = 35 minutes Part (a) Through what angle (in radians) will the second hand turn before the end of class? Numeric : A numeric value is expected and not an expression. Oseconds . Part (b) Through what angle (in radians) will the minute hand sweep before the end of class? Numeric : A numeric value is expected and not an expression. Ominute =. Part (c) Through what angle (in radians) will the hour hand sweep before the end of class? Numeric : Anumeric value is expected and not an expression. Ohour = Part (d) Calculate the angular velocity of the second hand in radians per second. Numeric : A numeric value is expected and not an expression. Wseconds = Part (e) Calculate the angular velocity of the minute hand in radians per second.…

While sitting in physics class one day, you begin to ponder the workings of the analog clock on the classroom wall. You notice as the hands sweep in a continuous motion that there are exactly t = 55 minutes left in class. Through what angle (in radians) will the second hand turn before the end of class?

A record is played by spinning the record so that a circular groove in the vinyl slides under the stylus.  Suppose that a record turns at a rate of 33 1/3 rev. min, the groove being played is at a radius of 10.0 cm and the bumps in the grove are uniformly separated by 1.75 mm.  At what rate (hits per second) do the bumps hit the stylus?  Enter units as hertz (Hz).  You will need v=rω ω is in rad/s and 1rev = 2 pi rad.

How would  I begin to solve this problem? In Example 2.6, we considered a simple model for a rocket launched from the surface of the Earth. A better expression for a rocket's position measured from the center of the Earth is given by y(t) = (RE3/2 + 3*(g/2)1/2 REt)2/3 where RE is the radius of the Earth (6.38 ✕ 106 m) and g is the constant acceleration of an object in free fall near the Earth's surface (9.81 m/s2). (a) Derive expressions for vy(t) and ay(t). (Use the following as necessary: g, RE, and t. Do not substitute numerical values; use variables only.)