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.
Answer:

Explanation:
Given that
x= 150 ft

y= 14 ft
From the diagram

When ,x= 150 ft and y= 14 ft


z=150.74 ft

By differentiating with respect to time t


Here x is constant that is why


Now by putting the values in the above equation we get



Therefore the distance between balloon and observer increasing with 0.65 ft/s.
The equation for electrical power is<span>P=VI</span>where V is the voltage and I is the current. This can be rearranged to solve for I in 6(a).
6(b) can be solved with Ohm's Law<span>V=IR</span>or if you'd like, from power, after substituting Ohm's law in for I<span>P=<span><span>V2</span>R</span></span>
For 7, realize that because they are in parallel, their voltages are the same.
We can find the resistance of each lamp from<span>P=<span><span>V2</span>R</span></span>Then the equivalent resistance as<span><span>1<span>R∗</span></span>=<span>1<span>R1</span></span>+<span>1<span>R2</span></span></span>Then the total power as<span><span>Pt</span>=<span><span>V2</span><span>R∗</span></span></span>However, this will reveal that (with a bit of algebra)<span><span>Pt</span>=<span>P1</span>+<span>P2</span></span>
For 8, again the resistance can be found as<span>P=<span><span>V2</span>R</span></span>The energy usage is simply<span><span>E=P⋅t</span></span>
The tangent looks good.
The curve is a bit crooked, at the 0.9 and 1.
But overall, cool graph.
Answer:
The lowest possible frequency of sound is 971.4 Hz.
Explanation:
Given that,
Distance between loudspeakers = 2.00 m
Height = 5.50 m
Sound speed = 340 m/s
We need to calculate the distance
Using Pythagorean theorem




We need to calculate the path difference
Using formula of path difference

Put the value into the formula


We need to calculate the lowest possible frequency of sound
Using formula of frequency

Put the value into the formula


Hence, The lowest possible frequency of sound is 971.4 Hz.