Answer:
Distance between P and R is 40.15 km.
Step-by-step explanation:
From the picture attached,
Petrol kiosk P is 12 km due North of another petrol kiosk Q.
Bearing of a police station R is 135° from P and 120° from Q.
m∠QPR = 180° - 135° = 45°
m∠PQR = 120°
m∠PRQ = 180° - (m∠QPR +m∠PQR)
= 180° - (45° + 120°)
= 180° - 165°
= 15°
Now we apply sine rule in ΔPQR to measure the distance between P and R.
PR =
PR = 40.15 km
Therefore, distance between P and R is 40.15 km.
Answer:
radius r = 47/π in
length l = 23.5 in
Step-by-step explanation:
Let us recall that:
Volume of a cylinder = --- (1)
The girth g = ----- (2)
Given that:
height (h) + girth (g) = 141
Then g = 141 - h ----- (3)
Equating equation (2) and (3), we have:
141 - h = 2πr + h
2h = 141 - 2πr
h = 70.5 - πr ------ (4)
From, here now, we can now replace the value of h into equation (1)
i.e.
V = πr²(70.5 - πr)
V = 70.5πr² - π²r³
Taking the differential of the above equation with respect to r, we have:
By further differentiation:
Let set , Then:
141πr - 3π²r² = 0
141πr = 3π²r²
Divide both sides by πr
141 = 3πr
r = 141/3π
r = 47/π in
Replacing the value of r = 47/π into equation (4), we have:
h = 70.5 - πr
h = 70.5 - π(47/π)
h = 70.5 - 47
h = 23.5 in
From equation (3);
h + g = 141
23.5 + g = 141
g = 141 - 23.5
g = 117.5 in
Volume = πr²h
V = π × (47/π )² × 23.5
V = 16523.94 in³