Answer:
230.4 s
Explanation:
The speed of car A is
and the distance travelled is
so the time taken for car A is
The speed of car B is
and the distance travelled is
so the time taken for car B is
So the difference in time is
Which corresponds to
so car B arrived 230.4 s before car A.
D= m/v
d= 6200/2296
density = about 2.7
Answer:
The SI unit of intensity is the watt per square meter/metre (W/m^2.)
Explanation:
Intensity is equal to the power transferred per unit area. Since power is measured in watts (W) and 1 W = 1 J/s, then intensity can be viewed as how fast energy goes through a certain area.
In physics, intensity is often used when studying light, sound, or other phenomena that involve waves or energy transfer. (With waves, the power value is taken as the average power transfer over the wave's period.)
Answer: True.
Explanation:
The US constitution has involved details related to the Supreme Court; in fact, the US constitution created this institution. However, the structure does not specify how many judges will sit in the supreme court. Those details were left to the US Congress. In 1807, Congress increased the number of judges to seven; In 1837 the number increased to nine, and in 1863 it rose to 10.
Answer:
67
Explanation:
- The atomic number (Z) of an atom is equal to the number of protons in the nucleus
- The mass number (A) of an atom is equal to the sum of protons and neutrons in the nucleus
Therefore, calling p the number of protons and n the number of neutrons, for element X we have:
Z = p = 23
A = p + n = 90
Substituting p=23 into the second equation, we find the number of neutrons:
n = 90 - p = 90 - 23 = 67
