Answer:
The distance between them after 30 minutes is 6.5 km.
Step-by-step explanation:
Speed = 
Sarah's speed = 6 km/hr = 1.6667 m/s
Emily's speed = 10 km/hr = 2.7778 m/s
The measure of angle between their bearings = 
After 30 minutes (1800 seconds);
distance = speed x time
Sarah would have covered a distance = 1.6667 x 1800
= 3000 m
= 3 km
Emily would have covered a distance = 2.7778 x 1800
= 5000 m
= 5 km
The distance between them, a, can be determined by applying the cosine rule;
=
+
- 2bcCos A
=
+
-2(5000 x 3000) Cos 105
=
+
-2(5000 x 3000) x (-0.2588)
= 2.5 x
+ 9 x
+ 7764000
= 41764000
a = 
= 6462.5073
a = 6462.5 m
The distance between them after 30 minutes is 6.5 km.
Answer:
Solution given:
perpendicular [P]=15m
base[B]=8m
hypotenuse [H]=17m
rate :4 plants per square metre
no of plants=?
we have
Area of triangular garden: ½(P*B)=½(15*8)=60m²
Now
Total no of plants =rate ×Area =4×60=240
Michael needs <u>240</u> plants in the garden
Answer:
Step-by-step explanation:
- The speed of the boat in the lake = x
- The speed of the current = 3 km/h
<u>Required equation:</u>
- 54 / (x + 3) + 42 / (x - 3) = 96/x
- 9x(x - 3) + 7x(x + 3) = 16(x + 3)(x - 3)
- 9x² - 27x + 7x² + 21x = 16x² - 144
- 6x = 144
- x = 144/6
- x = 24 km/h