Explanation:
In order to find out if the keys will reach John or not, we can use the formula of projectile motion to find the maximum height reached by the keys:
H = V²Sin²θ/2g
where,
V = Launch Speed = 18 m/s
θ = Launch Angle = 40°
g = 9.8 m/s²
Therefore,
H = (18 m/s)²[Sin 40°]²/(2)(9.8 m/s²)
H = 6.83 m
Hence, the maximum height that can be reached by the projectile or the keys is greater than the height of John's Balcony(5.33 m).
Therefore, the keys will make it back to John.
The sample appears to have gone through 3 half-lives
1st half life: 1000 to 500 g
2nd half life: 500 to 250 g
3rd half life: 250 to 125 g
The duration of a half-life, therefore, can be inferred to be 66 ÷ (3) = 22 days.
After a 4th half life, there will be 125÷2= 62.5 g.
At this point, an additional 22 days will have passed, for a total of 88 days.
Answer is C.
The answer to this question is B I think
Answer:
18.1347 m/s
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
g = Acceleration due to gravity = 9.81 m/s² = a

Total height the ball falls is 2.4619+14.3 = 16.7619 m

The speed at which the stone reaches the ground is 18.1347 m/s
Answer:
Answer
Explanation:
The very first generation of star systems in the universe probably consisted only of hydrogen and helium. This means that,
There were no comets or asteroids in these first-generation star systems. As the comets and asteroids were the only soruce of elements other than Hydrogen and Heliums ( As starts mainly consists of helium and hydrogen).