Velocity, frequency of sound

1.A supersonic jet traveling at Mach 3 at an altitude of 20000m is directly overhead at time t=0. A) How long will it be before the ground observer encounters the shock wave? B)Where will the plane be when it is finally heard?(Assume an average value of 330m/s for speed of sound in air) I will send what I have for this one as attachment. Just incase you can't see the numbers.. I have the plane 56478m away from the person and at an angle of 19.5degrees and the person hears the sound 181secs after it flies over him. 2.Expectant parents are thrilled to hear their unborn baby's heartbeat, revealed by an ultrasounic motion detector. Suppose the fetus's bentricluar wall moves in simple... click for more

Rate of formation of ice in a lake

Find the time in which a layer of ice 3cm thick on the surface of a pond will increase its thickness by 1mm when the temperature of the surrounding air is -200 C. Thermal conductivity of ice = 0.005, Latent heat of ice = 80cal/g and the density of ice at 00 C = 0.91g/cm3

Determine the principal stresses and the maximum shear stress in a spindle

The pedal crank of a racing cycle is to be analysed to assess whether the stresses are excessive. Pedal loads can reach 500N (causing bending) and produce a torque of 100Nm. The location of load application alternates each half rotation of the spindle (from locations A to F) as shown in the attached diagram. Determine the principal stresses and the maximum shear stress at the bearings (ie locations B and D) and also at the mid-spindle position C under the most adverse loading.

Determine the maximum stress in a mast

NOTE: MOVED TO PHYSICS FROM MECHANICAL ENGINEERING The mast of a racing yacht stands 22m above the deck and is rigidly attached to the hull and keel. The mast supports a triangular sail which is 20m high and 4m wide at the boom and may be idealised as shown in the diagram. The mast is constructed using 250mm outside diameter and 30mm wall thickness CFRP and the core is filled with foam filler. Along the axial direction the CFRP has an effective elastic modulus of 80 GPa and tensile strength of 380 MPa. The foam filler has an elastic modulus of 10 GPa with no significant strength. Determine the maximum stress in the mast when the wind speed, v is 25 m/s. The following assumption... click for more

Electrical Energy and Capacitance

1. On planet Tehar, the free fall acceleration is the same as that on Earth but there is also strong downward electric field with the field being uniform close to the planet's surface. A 2.00 kg ball having a charge of 5.00 mC is thrown upward at a speed of 20.1 m/s and it hits the ground after an interval of 4.10 s. What is the potential difference between the starting point and the top point of the trajectory? 2.An electron starts from rest 3.00cm from the center of a uniformly charged sphere of radius 2.00cm. If the shpere carries a total charge of 1.00 * 10^-9C, how fast will the electron be moving when it reaches the surface of the sphere? 3.A certain storm cloud has a potential ... click for more