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Classical Mechanics - Velocity of a bullet and a Bicyclist

A passenger at rest on a flatbed train car fires a bullet straight up. The event is viewed by observers at rest on the station platform as the train moves past the platform with constant velocity. What is the trajectory of the bullet as described by the observers on the platform? A a straight horizontal path in the directi

Relativistic formulas

At what velocities do the relativistic formulas for length contraction and time dilation give a 1% difference from classical values?

A baseball is hit from a height of 0.8m

1) A baseball is hit from a height of 0.8m. After t seconds. its height h, in metres is measured by h = -5t^2 + 20t + 0.8 a) use the method of completing the square to find the maximum height of the ball? b) How long is the ball in the air?

Physics: Calculate the average force of particles colliding with a wall

What is the average force associated with 100 * 10^6 particles, each of a mass 8.280912E-06 Kg, colliding elastically with a wall at a velocity of 102.1 m/s, with directions randomly distributed in 3 dimensions? Assume that the wall is one of the parallel walls of a cylinder with the walls separated by 3 meters.

Kinematics: Determining Distance Traveled From Average Velocity

In reaching her destination, a backpacker walks with an average velocity of 1.14 m/s, due west. This average velocity results, because she hikes for 6.17 km with an average velocity of 2.53 m/s, due west, turns around, and hikes with an average velocity of 0.747 m/s, due east. How far east did she walk (in terms of km)?

Wave on a string: Amplitude, frequency, time, speed, distance

A wave on a string is described by the equation y=12cos(1.57 x - 6.28 t). The lengths are measured in cm and time is s. Determine, (a) the amplitude, frequency, and the the time it takes for the wave to repeat itself. (b) the speed of the wave and the distance a peak of the wave travels at 3T + .5 s.

Addition vector of two velocities

When a truck creeps along in traffic at a speed of 5 m/s, a man walks diagonally across the back of the truck at 3m/s. To a traffic helicopter in a stationary position above the road the road, the man's apparent motion is the superposition of these two motions; that is, his apparent velocity is the vector sum of the two given ve

Waves on a string

A brother and sister try to communicate with a string tied between two tin cans. If the string is 9.5 m long, has a mass of 32 g, and pulled taut with a tension of 8.6 N, how long does it take a wave to travel from one end of the string to the other?

Finding Ratio of Wave Speeds in Two Strings

Two steel guitar strings have the same length. String A has a diameter of 0.50 mm and is under 410.0 N of tension. String B has a diameter of 1.0 mm and is under a tension of 820.0 N. Find the ratio of the wave speeds, vA/vB, in these two strings.

What is the final speed at the end of that displacement?

1. A car slowed from 30 m/s to 20 m/s in 50. m. How long did it take for this to happen? 2. An auto with an initial velocity of 7.0 m/s accelerates at 0.71 m/s^2. It travels a distance of 1.0 km while accelerating. What is the final speed at the end of that displacement?

Physics: How tall is the building?

1. A steel ball bearing is dropped from the roof of a building. An observer standing in front of a window 120 cm high notes that the ball takes 0.125s to fall from the top to the bottom of the window. The ball bearing continues to fall, makes a completely elastic collision with a horizontal sidewalk, and reappears at the bottom

A 50 g ball of putty

A 50 g ball of puty moving with a velocity of 3.0 m/s has an inelastic collision head on with a stationary mass of 50 g and sticks to it. find the velocity of the mass and putty after the collision a. 1.7 m/s b. 1.1 m/s c. 1.5 m/s d. 1.3 m/s

Recoil velocity calculation

A 37.0 kg child standing on a frozen pond throws a 0.500 kg stone to the east with a speed of 6.00 m/s. Ignoring friction between the child and the ice, find the recoil velocity of the child. (Assume the positive direction is to the east.) m/s

Solving for Pressure and Velocity

Question: The artery is 2/3 blocked. The normal speed is 0.40 m/s and blood density is 1060 kg/m^3. Find the velocity of the blood at the blocked area. Find the pressure difference between the normal and blocked area.

Velocities of the bowling balls after the collision

1) A 3 kg bowling ball traveling with a velocity of 3 m/s collides head-on with another bowling ball of the same mass traveling with a velocity of -2 m/s. If the collision is perfectly elastic, the velocities of the bowling balls after the collision is: a. 2 m/s an -3 m/s b. 5 m/s and 0 c/-2 m/s and -3 m m/s/s d. -2m/s and

Airplane flight wing pressure

During level airplane flight at a constant velocity, the pressure created by air flowing over the curved upper surface of the wing compared to the pressure created by air flowing along the flat underside of the wing is a. less b. insufficent data c. the same d. more

Dynamics: Speed, Velocity, Angle, etc.

1. Find the total energy of the system at the given instant if the 20 kg disc has an angular velocity of 24 rad/s (clockwise), the bar AB has a mass of 2 kg, and the system is 1.5 meters above the ground. Assume the ground as the datum line (zero potential energy). a. 353 J b. 389 J c. 294 J d. 323 J e. 429 J

Find the velocity of the block/bullet system immediately after the collision.

A 3.16 kg block of wood rests on the muzzle opening of a vertically oriented rifle, the stock of the rifle being firmly planted on the ground. When the rifle is fired, an 8.10 g bullet (velocity = 850 m/s, straight upward) becomes completely embedded in the block. (a) Using the conservation of linear momentum, find the velocity

Method of Subsitution : Velocity from Displacement and Acceleration

In science, we calculate the displacement of an object (how far it travels) and the velocity of an object (how fast it is moving) using the Displacement Equation and the Velocity Equation. where x is the displacement of the object, measured in meters t is the amount of time that we analyze the movement of the object, m

Falling steel I-beam

If a steel I-beam falls from the top of a 96 foot high building, how long before it hits the ground? (if an object is given an initial velocity v feet per second from a height of S feet it's height after t seconds is given by: S = -16t^2 + vt + s)

Momentum of a Particle

The momentum of a particle is proportional to the square of its velocity. True or false? Please also explain why.

Turbomachinery: Impulse & Reaction Turbines

Question 4: An impulse air turbine has a total (on static) inlet pressure and temperature of 11,25 bar, 600 degrees K and exhausts to the atmosphere at 0.91 bar. The nozzle efficiency is 87% and its exit angle is 71 degrees. The rotor efficiency is 65%. If the blade speed if 190 m/s at the mean radius of 12cm, calculate the powe

Angular Speed and Velocity

A merry-go-round makes 24 revolutions in a 3.0-min ride. (a) What is it's average angular speed in rad/s? (b) What are the tangential speed of two people 4.0 m and 5.0 m from the center, or axis of rotation?

Determine the Thermal Efficiency

An aircraft is flying at true airspeed of 270m/s, each jet engine producing 10,000 lb max thrust for a fuel flow of 0.3 kg/s. Noting that the lower calorific value of AVTUR (Jetfuel) is 42 MJ/kg, determine the engine's overall thermal efficiency in this operating condition.