Answer: A
Explanation:
Isotopes of different elements differ by the number of neutrons inside the nucleus.
Answer:
The period saw major technological advances, including the adoption of gunpowder, the invention of vertical windmills, spectacles, mechanical clocks, and greatly improved water mills, building techniques (Gothic architecture, medieval castles), and agriculture in general (three-field crop rotation).
Explanation:
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Answer:
LAW 1 : For a given metal and frequency, the number of photoelectrons emitted is directly proportional to the intensity of the incident radiation.
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LAW 2: For a given metal, there exists a certain frequency below which the photoelectric emission does not take place. This frequency is called threshold frequency.
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LAW 3: For a frequency greater than the threshold frequency, the kinetic energy of photoelectrons is dependent upon frequency or wavelength but not on the intensity of light.
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LAW 4: Photoelectric emission is an instantaneous process. The time lag between incidence of radiations and emission of electron is 10^-9 seconds.
Explanation:
Answer:
A.) 1372 N
B.) 1316 N
C.) 1428 N
Explanation:
Given that a 140 kg load is attached to a crane, which moves the load vertically. Calculate the tension in the cable for the following cases:
a. The load moves downward at a constant velocity
At constant velocity, acceleration = 0
T - mg = ma
T - mg = 0
T = mg
T = 140 × 9.8
T = 1372N
b. The load accelerates downward at a rate 0.4 m/s??
Mg - T = ma
140 × 9.8 - T = 140 × 0.4
1372 - T = 56
-T = 56 - 1372
- T = - 1316
T = 1316N
C. The load accelerates upward at a rate 0.4 m/s??
T - mg = ma
T - 140 × 9.8 = 140 × 0.4
T - 1372 = 56
T = 56 + 1372
T = 1428N
