Beijing Olympics: The Mechanics of the Tyson Bolt 100m Race

A) By studying video footage, it can be seen that Bolt took 41 strides in total over the 100 m. 29 strides were taken in the last 80 m, and 18 strides were taken during the second 50 m of the race. Calculate the average length of his stride over 100 m, 80 m and 50 m respectively. B) Using the dat...

Ideal solutions concerning rotating solid and hollow shafts

3a. A solid shaft of diameter 30mm rotating at 1000rpm delivers a power of 25kW determine (assume Shear Modulus for the shaft, G=80 GPa) The Shear Stress in the shaft The angular twist of the shaft as a result of the Shear Stress from part (i) The important parameters to note here are ...

What is the power needed to accelerate a flywheel?

Please see the attached file for full problem description. I need to calculate torque for this question: A gearbox and flywheel are as shown in FIGURE 4 (attached). The output shaft rotates in the opposite direction to the input shaft at 5 times its speed. The gearbox has an efiiciency of 92...

Heat Transfer Problem: Transient Solutions

See the attached file. Molybdenum is utilized in high temperature situations because of it high melting point. It is silvery white in color, very hard, and has one of the highest melting points of all pure elements. Molybdenum on Earth is not found free but as a compound. The only pure Molybdenum...

Balancing masses on a shaft supported by two bearings

1. A shaft 2m long 1500 rev min-1 between the bearing shown in figure below. Bearing have forces 5kN and 3kN acting in same plane as shown. A single mass is to be used to balance the shaft so that reactions are zero. The mass is to be placed at a radius of 200mm from the shaft centre 180° from the...

A simple torque question

A 1000 lb uniform platform is rotated by a green shaft (centered) as shown. The ends of the green shaft are each connected to a motor - one on either side of the platform. If the platform starts out from rest in horizontal position, how much torque is need to rotate this platform 180 degrees in 3 se...

Heat Loss Calculations for a Spherical Martian Surface

See attached for the question with the accompanying diagram. A spherical habitat is built under the Martian surface. There is power generation in the habitat. This causes the surface to be at a uniform temperature of 30˚C. The Martian surface is at a uniform temperature of 10˚C. Calculate the ...

Deflection of Loaded Beam, Simply Supported

I'm trying to determine the position and magnitude of the maximum bending moment. As well as plotting a graph of the deflection along the length of the beam at 1 m intervals. I'm trying to use Macaulay's method and have got equations for slope and delection and the constants of integration but belie...

Equations of Force and Torque Equilibrium

Question deals with a leaning platform supported by three springs and a point loan on top. see file for specifics. Given: Looking down on platform supported by three springs arranged in an isosceles triangle pattern. Spring constant for orange springs =k1. Spring constant for purple spring =k2....

Electrolysis - Aluminium extraction

a. Aluminium is extracted from its ore by an electrolytic process. One extraction plant uses an applied e.m.f. of 5 V, and a current of 225 000 A. One tonne of aluminium is extracted after 14 hours. i. What is the power consumption of the electrolysis? ii. What is the effective electrical resist...

Stress-strain and fracture toughness

(a) Sketch the typical stress-strain curve for a metal and a ceramic. Using the sketch, indicate the following properties; elastic and plastic regions, yield points, Ultimate Tensile Strength (UTS), strain energy and fracture toughness. (b) A cylindrical specimen of a titanium alloy with a Young's...

Jack Screw Friction Force

A jack-screw has a handle 35 inches long and a pitch of 7/32 inches. If a pull of 15 lbs. is required at the end of the handle to lift a 3,000 lbs. load, what is the force expended to overcome friction?

Thurst Specific Fuel consumption of a Turbofan engine

The question : A turbofan engine on a test stand in the maintenance shop is being run at a continuous setting of 22,700 lbs of thrust. The TSFC is 0.5 lbs/lb-h. A fuel reservoir of 1000 gallons of JET A is feeding the engine. How long can it run at this power setting in minutes? A gallon of JET A...

Estimating fractions of a cost

Estimate what fraction of the price of a pocket calculator is required to cover the cost of developing the product. Based on producing half a million calculators per year.

Maximum load P

Please see the attached file. Three plates are joined with a 12 mm diameter pin as shown. Determine the maximum load P that can be transmitted by the joint if: a) The maximum normal stress on a cross-section of the plates at the pin must not exceed 400 MPa. b) The maximum bearing stress betwee...

Normal and Shearing Stresses

A steel pipe of 400 mm outer diameter is fabricated from 10 mm thick plate by welding along a helix that forms an angle of 20 degrees with a plane perpendicular to the axis of the pipe. Knowing that a 250 kN axial force P is applied to the pipe, determine the normal and shearing stresses in directio...

The Magnitude of the Largest Force P

Knowing that the ultimate load for cable BD is 100 kN and that a factor of safety of 3.2 with respect to cable failure is required, determine the magnitude of the largest force P that can be safely applied as shown to member ABC.

Pressure Study - System Interaction

Phase 1 Initially ALL Valves A, B, C, D, E and F are closed. ALL Tanks A, B, C, D, E are separated and each sealed from the atmosphere. Tank E initially has 3' of air @ 40 psi Tank C and Tank B initially contain air @ 32.476 psi Pipe K is 12" id; initial air pressure is 32.476 psi Phase 2 ...

Pressure Studies 1.6 Tank A B C&D

Please see full description in attached document. Phase 1 Initially Valves A, B, and E are closed. Tank A and B are separated and each sealed from the atmosphere. Tank A initially has 3' of air @ 40 psi Tank C and Tank B initially contain air @ 32.476 psi Pipe K is 12" id; initial air pressu...

Static Engineering System for Stress & Bending Moments

This question involves maximum bending moment calculation, maximum stress calculation, graph sketches of tensile & compressive stress dimensions for cross sections that minimize stress with given values and % reduction of maximum stress with new calculated cross sections. See attachment for prob...

static engineering systems for stress and bending moments

As per attachement. includes; maximum bending moment maximum stress in a beam graph sketches for tensil and compressive stresses dimensions for cross section that minimise stress with given values percentage reduction of the maximum stresswith new calculated cross section

A Body Moving with Simple Harmonic Motion

A body moving with simple harmonic motion has a velocity of 44.5mm/s and an acceleration of 20mm/s^2 when passing through a point 80mm from the centre of its path. Calculate the periodic time, the amplitude and the maximum force on the body if its mass is 100kg. Please see attachment for original qu...

Simple Harmonic Motion Frequency

A body moving with Simple Harmonic Motion with a frequency of 3Hz has a maximum velocity of 2.5m/s. Find its velocity. Please see attached file for further details regarding problem. Question - Simple Harmonic Motion A body moving with Simple Harmonic Motion with a frequency of 3Hz has a maxim...

Conical friction clutches

The mean diameter of a conical friction clutch is 250mm with a width of the conical surface being 50mm. The clutch is lined with a material having a coefficient of friction of 0.25. The angle of the cone being 50o. Find the greatest power that will be transmitted at 1200rpm together with the least a...

Epicycle Gear Question

If in the epicycle gear train in the drawing attached, gear C is fixed and the shaft X rotates at 650rpm, determine the speed of the shaft Y. All gears are of the same pitch and the number of teeth in A is 18, in B is 55 and in C is 60, D is 24 and E is 28.