From the choices given, ultraviolet rays is a type electromagnetic radiation that causes certain substances to fluoresce. It cannot be detected by the naked eye but some insects are able to see them.
Like in a fluorescent light bulb, ultraviolet or UV lights stimulates the coating of the tube to emit light.
Answer:
B. 22,22,23,23,22,22,23
Explanation:
The standard deviation is a measure of dispersion or variability of a data set. In order to determine the data set that has the smallest standard deviation, we shall investigate on the ranges of the data sets given. The range of a data set is simply the difference between the maximum and minimum values in a data set. A data set that has a smaller range also has a smaller standard deviation.
From the alternatives given, the data set given by alternative B has the smallest range and consequently the smallest standard deviation.
The maximum value is 23 while the minimum is 22. The range is 1.
The bimetallic strip in a fire alarm is made of two metals with different expansion rates bonded together to form one piece of metal. Typically, the low-expansion side is made of a nickel-iron alloy called Invar, while the high-expansion side is an alloy of copper or nickel. The strip is electrically energized with a low-voltage current. When the strip is heated by fire, the high-expansion side bends the strip toward an electrical contact. When the strip touches that contact, it completes a circuit that triggers the alarm to sound. The width of the gap between the contacts determines the temperature that will set off the alarm.
Answer:
Explanation:
Conservation of momentum during the collision
0.023(230) + 2.0(0.0) = 0.023(170) + 2.0v
v = 0.69 m/s
The initial block kinetic energy will be converted to friction work
½mv² = Fd = μmgd
½(2.0)(0.69²) = 0.15(2.0)(9.8)d
d = 0.1619387... m
d = 16 cm
