Explore BrainMass
Share

# Velocity

### 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?

### Solving for Harmonic Motion

Question: A body oscillates with simple harmonic motion along the x-axis. Its displacement varies with time according to the equation x=5(pi/t +pi/3). The velocity (in m/s) of the body at t=1 second is equal to what value?

### Centripetal force: Force exerted by the rope

A 50 kg ice skater is moving at 5m/s when she grabs the loose end of the rope,the opposite end of which is tied to a pole.She then moves in a circle of radius 1M around the pole.What is the force exerted by the rope on her arms? I think F=M*V^2/r =250N am I right?

### Rate of Change of Volume and Diameter of a Tree, Acceleration and Velocity Functions

According to the Doyle log rule , the volume V in broad feet of a log of length L (feet) and diameter D (inches) at the small end is V= (D-4/4)^2 *L Find the rate at which the volume is changing with respect to D for a 12-foot long log whose smallest diameter is a.) 8 inches, b.) 16 inches, c.) 24 inches, and d.) 36 inche

### Linear Momentum of a Billiard Ball

A billiard ball approaches the rail at a speed of 15 m/s and an angle of 60 degrees, but rebounds at a speed of 10 m/s and an angle of 50 degrees. What is the change in momentum and use components?

### Paths Through a Uniform Magnetic Field, Solenoids and Net Magnetic Field

1) The figure (*see attachment) shows 11 paths through a region of uniform magnetic field. One path is a straight line; the rest are half circles. The table (*see attachment) gives the masses, charges and speeds of the 11 particles that take these paths through the field in the direction shown. Which path corresponds to which pa

### Rates of Change : Velocity and Displacement

1.) Suppose a car starts from a stop sign and moves along a straight road. Assume the distance traveled in t seconds is given by s (t) + t^2 = 3t. a.) How far has the car traveled after 5 seconds? [ find s(5) ] b.) The speed of the car at exactly 10 seconds after "flooring it", can be estimated by finding the average speed

### Dynamics (Angular Velocity, Angular Acceleration)

2 practice quiz problems which I need help on. Please give explanation of each problem as well as the answer: 1) Member AB rotates about pin A at a constant 10 rad/s. What is the acceleration of point C at the instant shown? a) 13.4m/s^2 b) 7.51m/s^2 c) 17.2 m/s^2 d) 11.5 m/s^2 e) 9.63 m/s^2 2) Wheel A rotates counte

### Noether's theorem

Translate Noether's theorem into Hamiltonian mechanics. That is, define a symmetry for Hamiltonian mechanics (by translating the Lagrangian-definition), and prove that symmetries give rise to conserved observables.

### Kinematics Physics Experiments

Francesca, who likes physics experiments, dangles her watch from a thin piece of string while the jetliner she is in takes off from Dulles Airport . She notices that the string makes an angle of 25° with respect to the vertical while the aircraft accelerates for takeoff, which takes about 13.5 seconds. Estimate the takeoff spee

### Wave parameters and equation

1) A transverse traveling wave on a cord is represented by D = 0.48 sin (5.6x +84t) where D and x are in meters and t in seconds. For this wave determine (a) the wavelength (b) the frequency (c) velocity (magnitude and direction) (d) amplitude and (e) maximum and minimum speeds of particles of the cord.

### A Swimmer's Projectile Motion

A swimmer is capable of swimming 0.95 m/s in still water. (a) If she aims her body directly across a 150 m wide river whose current is 0.55 m/s, how far downstream (from a point opposite her starting point) will she land? (m) (b) How long will it take her to reach the other side?(s)

### Projectile Motion - Velocity, Magnitude and Direction

A passenger on a boat moving at 1.20 m/s on a still lake walks up a flight of stairs at a speed of 0.50 m/s. The stairs are angled at 45° pointing in the direction of motion as shown. What is the velocity of the passenger relative to the water? Find the magnitude (m/s) and direction (above the water). See the attached for t

### Explanation of Projectile Motion

Question: A projectile is shot from the edge of a cliff 285 m above ground level, with an initial speed of vo=135 m/s and at an angle of 37.0 degrees with the horizontal, as shown in the attached figure. Please view attachment. a) Determine the time taken by the projectile to hit point P at ground level. b) Determine the ra

### A Ball is Thrown

(1) A ball is thrown horizontally from a height of 20.8m and hits the ground with a speed that is three times its initial speed. What was the initial speed? (2) A ball is shot from the ground into the air. At a height of 9.1m, the velocity is observed to be V = 7.9i + 5.1j in m/s (i horizontally, j upward). To what maximum he

### Projectiles and Vectors Formats

1. a) A projectile is fired horizontally from a gun that is 37.0 m above the flat ground. The muzzle velocity is 275 m/s. How long does the projectile remain in the air? b) At what horizontal distance from the firing point does it strike the ground? c) What is the speed as it strikes the ground? 2. a) A watermelon has t

### Issues of Friction

I'm completely lost - Could you go step by step so I can follow your logic? Thanks. 1. A crate sits on a flatbed truck. This truck, initially travelling at a velocity of 80 km/hour, comes to a stop in 22 meters. What is the minimum coefficient of static friction required between the crate and truck bed, if it is not to sli

### Speed and Velocity Problem Set

1) A blink lasts 100 milliseconds. How far does one travel in meters, if the planes average velocity is 2040mph? 2) A particles position is x=5-12t+3t^2, v=6t-12. The velocity at 1 sec = 6m/s. Is it moving toward x just then? 3) What is its speed just then? 4) Is the speed larger or smaller at much later times? 5) At what

### Speed and Velocity

1) Jack travels from A to B at 30mph and returns at 10mph. Jill leaves at the same time as Jack, and travels from A to B and back at a constant speed of 20mph. Who gets back first? 2) Assume that East Lak Road runs due east from the Walmart and there are markers along it, ten miles from walmart, etc. a car starts at the 12

### Collision at an Angle

Two cars, both of mass m, collide and stick together. Prior to the collision, one car had been traveling north at speed 2v, while the second was traveling at speed v at an angle omega south of east. After the collision, the two-car system travels at speed v_final at an angle theta east of north. What is the angle theta with resp

### Calculating Magnitude of Force and Velocity

Consider a force F acting on a particle that moves with a velocity v for F=(6N)i - (5N)j and v = (-5 m/s)i + (4 m/s)j -What are the magnitudes of F and v?

The velocity of the slider block C is 4 ft/s up the inclined groove. Determine the angular velocity of links AB and BC and the velocity of point B at the instant shown. Links AB and BC are both 1ft in length. (See attachment for full question.)

### Angular Velocities of a Pulley

If the end of the cord is pulled downward with a speed Vc= 120mm/s, determine the angular velocities of pulleys A and B and the speed of block D. Assume that the cord does not slip on the pulleys. (See attachment for full question.)

### Projectile Motion with Coefficient of Restitution

The ball is ejected from the tube with a horizontal velocity of v1= 8ft/s as shown. If the coefficient of restitution between the ball and ground is e=0.8, determine (a) the velocity of the ball just after it rebounds from the ground and (b) the maximum height to which the ball rises after the first bounce (see attachment for di

### Pilots can be tested for the stresses of flying high speed jets in a whirling human centrifuge.

1) Automobile engine slows down from 4500 rpm to 1200 rpm in 2.5 s. Calculate (a) its angular acceleration, assumed constant, and (b) the total number of revolutions the engine makes in this time. 2) Pilots can be tested for the stresses of flying high speed jets in a whirling "human centrifuge," Which takes 1.0 min to turn t

### Average Landing Force Needed

A person about to jump from a 1.6m high platform wants to limit the average stopping force on landing to 12 times her weight. By how much will it be necessary to lower herself by flexing her knees? Give an algebraic rather than numerical answer. Compare that work with the original potential energy she had before she jumped.

### Physics Wave Problems

11. A particle in simply harmonic motion has a frequency of 40 Hz. What is the period of this oscillation? 17. (a) At what position is the speed of mass in a mass-spring system maximum? (1) x = 0, (2) x = -A, or (3) x = +A. Why? (b) If m = 0.250 kg, k = 100 N/m, and A = 0.10 m, what is the maximum speed? 33. The simple pe

### Hitting a tennis ball - the magnitude of the net impulse

The tennis ball has a horizontal speed of 15 m/s when struck by the racket. If it then travels away at an angle of 25 deg from the horizontal and reaches a maximum altitude of 10m, measured from the height of the racket, determine the magnitude of the net impulse of the racket on the ball. The ball has a mass of 180g. Neglect th

### Impulse of foot kicking soccer ball

A man kicks a 200g ball such that it leaves the ground at an angle of 30 deg. with the horizontal and strikes the ground at the same elevation a distance of 15m away. Determine the impulse of his foot on the ball. Neglect the impulse caused by the ball's weight while its being kicked. **answer should be 2.61 N*s**