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Velocity

Vertical Circular Motion

In an automatic clothes drier, a hollow cylinder moves the clothes on a vertical circle (radius r = 0.27 m), as the drawing shows. The appliance is designed so that the clothes tumble gently as they dry. This means that when a piece of clothing reaches an angle of above the horizontal, it loses contact with the wall of the cyli

Angular Displacement of a Baseball

A pitcher throws a curveball that reaches the catcher in 0.53 s. The ball curves because it is spinning at an average angular velocity of 335 rev/min (assumed constant) on its way to the catcher's mitt. What is the angular displacement of the baseball (in radians) as it travels from the pitcher to the catcher?

impulse applied to volleyball

A volleyball is spiked so that its incoming velocity of +3.8 m/s is changed to an outgoing velocity of -19 m/s. The mass of the volleyball is 0.38 kg. What impulse does the player apply to the ball?

The Normal Force of a Sled

A 16.5 kg sled is being pulled across a horizontal surface at a constant velocity. The pulling force has a magnitude of 85.5 N and is directed at an angle of 30.0° above the horizontal. Determine the coefficient of kinetic friction.

Physics: Velocity, Kinetic friction, Acceleration

1. Estimate the order of magnitude (exponential power) for the number of grains of salt in a salt shaker. 6. The world record for falling out of an airplane, without a parachute and surviving is 10,000m. If b is 0.13 N(s/m)^2, what is the terminal velocity of this person, assuming she has a mass of 70 kg? 9. consider pushi

Frequency of Light

The red light associated with the Aurora Borealis is emitted by excited oxygen atoms at 6.60 X 10-7 m. What is the frequency of the light? Using scientific notation, (Round your answer to two decimal places) and write the exponent part as follows: x 10 to the _ power.

Length of Time a Ball is in the Air

A baseball is propelled upward with a speed of 128 feet per second from a height of 4 feet. For how many seconds is the ball higher than 244 feet?

Circular Motion

In uniform circular motion, the acceleration is perpendicular to the velocity at every instant. Is this true when the motion is not uniform, that is, when the speed is not constant?

Circular Motion in Cycling

Dan and Beatrice cycle side by side. The tires on Dan's bike are large in diameter than those on Beatrice's bike. Which wheels, if either, have the greater rotational speed? Explain.

The Velocity of a Rocket at Parigee of an Elleptic Orbit

Problem # 4 - The rocket is traveling in a free-flight elliptical orbit about the earth such that e = 0.76 and Its perigee is 9Mm as shown. Determine its speed when it is at point B. Also determine the sudden decrease in speed the rocket must experience at A in order to travel in a Circular orbit about the earth.

Angular velocity of a sphere and cylinder on an incline

A sphere and cylinder are released from rest on the ramp at t = 0. If each has a mass m and A radius r, determine their angular velocities at time t. Assume no slipping occurs. See attached file for full problem description.

Rotational Motion of a Motor

Problem: The man stands on the platform at O and runs out toward the edge such that when he is at A, y = 5 ft, his mass center has a velocity of 2 ft/s and an acceleration of 3 ft/s^2, both measured with respect to the platform and directed along the y axis. If the platform has the angular motions shown, determine the velocity

Two Particle System in Inertial Frames, and Newtonian Relativity

See the attached file. The question starts, Consider an isolated system comprising two particles of masses m1 and m2. Whose position vectors, in an inertial frame, are x1 and x2 and whose velocity vectors are v1 and v2. The interaction of the particles may be described by an energy function. E=1/2m1v1^2+1/2m2v2^2+U(x1,x

Positve and Negative Acceleration and Velocity

1. Discuss the validity of each of the following statements. Provide examples to support the answers. a) If the acceleration of an object is positive, it is speeding up. If the acceleration of an object is negative, it is slowing down. b) If the velocity of an object is positive, it is moving away from the origin. If the vel

Electric Current: Velocity of electron in a beam; Current of a beam

In a certain electron beam, there are 5.0 x 10^6 electrons per cubic centimeter. Suppose the kinetic energy of each electron is 10 keV and the beam is cylindrical with a diameter of 1 mm. (a) what is the velocity of an electron in the beam? (b) find the beam current.

S Inertial Frames

The following posting helps with problems involving inertial frames. See attached file for full problem description.

Determining Time Given Velocity: Ball Example

When a ball is thrown vertically upward, its height (h, in feet) above the ground after t seconds is described by the mathematical formula h = - 16t2 + 96t + 80. At what times is the ball 103 feet above the ground?

speed of boat in still water

Debbie traveled by boat 5 miles upstream to fish in her favorite spot. Because of the 4-mph current, it took her 20 minutes longer to get there than to return. How fast will her boat go in still water?

relative velocity and work done by the train

A train moves along the tracks at a constant speed u. A woman on the train throws a ball of mass m straight ahead with a speed v with respect to herself. a) What is the kinetic energy gain of the ball as measured by a person on the train? b) By a person standing by the railroad track? c) How much work is done by the woman

Average Velocity of a Particle

The position of a particle as a function of time is given by x(t) = (3.1 m/s)t - (4.2 m/s^2)t^2. What is the average velocity of the particle between t = 1.0 s and t = 2.0 s?

Magnitude of Average Velocity

A car moves from a point located 26.0 m from the origin and at an angle of 35.0 from the x-axis to a point located 56.0 m from the origin and at an angle of 60.0 from the x-axis in 2.50 s. What is the magnitude of the average velocity of the car? 12.7 m/s 13.7 m/s 16.1 m/s 18.3 m/s.

Speed of Baseball Player

A baseball player is running to second base at 5.63 m/s. When he is 5.20 m from the plate he goes into a slide. The coefficient of kinetic friction between the player and the ground is 0.220. What is his speed when he reaches the plate? 4.47 m/s 3.04 m/s 1.96 m/s He stops before reaching the plate.

Kinematics: How fast was the car going?

1) A policeman investigating an accident measures the skid marks left by a car. He determines that the distance between the point that the driver slammed on the brakes and the point where the car came to a stop was 34.0 m. From a reference manual he determines that the coefficient of kinetic friction between the tires and the ro

Value of angle x

A ball is thrown with a velocity of 40 m/s at an angle x above the horizontal. If the ball attains its maximum range, what was the value of the angle x?

Vertical Component of Velocity at Highest Point

A boy kicks a football with an initial velocity of 20 m/s at an angle of 30 degrees above the horizontal. What is the vertical component of its velocity at the highest point of its trajectory?

Horizontal component of velocity

A girl kicks a soccer ball with an initial velocity of 25 m/s at angle of 30 degrees above the horizontal. The horizontal component of the velocity of the ball is described by which of the following statements: It changes uniformly. It is zero. It is 25 m/s. It remains constant during the ball's flight.

Velocity and Acceleration for Travels

A car travels along east and its velocity decreases. The acceleration of the car is in which direction (northward, eastward, southward, or westward)? Explain.