Engineering, 25.09.2020 02:01 morrisjillian23
Carbon dating for archeological materials is based on the fact that a plant, after its death, stops absorbing radioactive C-14 as CO2 from the atmosphere. This radioactive carbon accounts for 0.10% of the total carbon content at death. After death, the C-14 decays at its characteristic rate. A piece of straw from a brick excavated from within an ancient ruin shows a C-14 content of 0.089%. Estimate the age of the ruin. (For C-14, T1/2 =5715 years)
Answers: 2
Engineering, 04.07.2019 16:10
An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)
Answers: 2
Engineering, 04.07.2019 18:10
Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk
Answers: 1
Engineering, 04.07.2019 19:10
Ahelical coil spring has a mean diameter of 50 mm, a wire diameter of 5.5 mm and is wound with a pitch of 10 mm. the spring steel has an ultimate strength of 1250 mpa. find the force needed to compress the spring solid and the wire stress in this condition. state whether the spring will return to its initial length.
Answers: 1
Engineering, 06.07.2019 03:10
List and describe in sequence the operation process steps for boxf machine?
Answers: 1
Carbon dating for archeological materials is based on the fact that a plant, after its death, stops...
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