A coil spring in an oscillating machine runs at between 500 and 1500 rpm (cycles per minute). The spring diameter is 50 mm and the wire diameter is 4 mm. The free length of the spring is 200 mm and the solid length is 80 mm. The ends are squared and held between flat, parallel plates. The spring is made of hard-drawn steel wire. Based on comparing the critical frequency and the range of operating frequencies, is this a good design? Given: For the specific weight of steel, use 77,000 N/m
a. Calculate the number of active coils, Na.
b. Calculate the approximate spring rate, k.
c. Calculate the weight of the spring, W.
d. Calculate the lowest critical frequency, f in cycles per second.
e. Is this an acceptable design?

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Select any two (2) areas of applications of chain-drive. (clo4) a)-permanent lubrication necessary b)-hydraulic forklift truck operation c)-rigging and heavy moving materials d)-relatively high maintenance costs e)-costlier than belt drives

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg. m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?