By the law of momentum conservation:-
=>m¹u¹ + m²u² = m1v1 + m²v² {let East is +ve}
=>u¹ + u² = v¹ + v² {as m1=m2}
=>3.5 - 2.75 = v1-1.5
<span>
=>v¹ = 2.25 m/s (East) </span>
Answer:
51.94 ft/s²
257.63 ft/s
Explanation:
t = Time taken = 4 s
u = Initial velocity = 34 mi/h
v = Final velocity
s = Displacement = 615 ft
a = Acceleration
Converting velocity to ft/s

Equation of motion

Acceleration is 51.94 ft/s²

Final velocity at this time is 257.63 ft/s
The mass number is the total number of protons and neutrons within an atom and since we know that the unknown element has 6 neutrons, we can simply subtract the number of neutrons from the mass number to get the number of protons.
17 - 6 = 11
There are 11 protons in this unknown element.
Extra:
The number of protons (+) and electrons (-) are equal in a neutral atom so since you know that there are 11 protons you also know that there are 11 electrons. On the periodic table, the element with 11 electrons is Na or Sodium.
Hope this helps! :)
Their inferences are based on evidence that they collect during their investigations. Readers learn that scientists gather and interpret evidence and draw conclusions based on this evidence. ... Once scientists have gathered evidence, they use it to make inferences about the things they are investigating.