Answer:
A. 260 mm
B. - 18
C. 175
Explanation:
A
The expression for the lens equation is
v = 259 mm
= 260 mm or 26 cm (to 2 s.f)
check the attached files for additional solution
It is (C): human.
This is more like forensic sciences or biology btw.
Answer: b- covection
Explanation:
Conduction: It is the circulation or transfer of heat through a metal or solid. For example, heat generated inside an enclosure can be transferred to the outer surface by means of conduction.so therefore conduction can not be the answer.
Convection is the circulation or tansfer of heat from a surface by means of a fluid such as air. Natural convection happens when air is heated: it expands, rises, and is replaced by cooler air. The amount of convection may be increased by using a fan to increase the flow of air.Likewise,Ducts are used to circulate air in the system. Since, air is circulated in the system, heat is transfered by convection.Hence,the answer is B-convection.
Radiation: Here, energy is radiated through the air by means of electromagnetic radiation. Since heat transfer through raidation does not involve contact between the heated object and the heated source,so energy is lost as light or through electromagnetic radiation. So C is wrong.
Answer:
Explanation:
Time period, T = 50 μs = 50 x 10^-6 s
Frequency is defined as the number of oscillations or vibrations completed in one second.
The reciprocal of time period is called frequency.
f = 1 / T
f = 1 / (50 x 10^-6)
f = 20,000 Hz
Angular frequency, ω = 2 x π x f
ω = 2 x 3.14 x 20,000
ω = 125600 rad/s
