E 40)7280 How do you solve this
1 answer:
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Answer:
a) 6 mins
b) 70km/h
c) t= 45
Step-by-step explanation:
a) The bus stops from t=10 to t=16 minutes since the distance the busvtravelled remained constant at 15km
Duration
= 16 -10
= 6 minutes
b) Average speed
= total distance ÷ total time
Total time
= 24min
= (24÷60) hr
= 0.4 h
Average speed
= 28 ÷0.4
= 70 km/h
c) Average speed= total distance/ total time
Average speed
= 80km/h
= (80÷60) km/min
= 1⅓ km/min
1⅓= 28 ÷(t -24)
<em>since</em><em> </em><em>duration</em><em> </em><em>for</em><em> </em><em>return</em><em> </em><em>journey</em><em> </em><em>is</em><em> </em><em>from</em><em> </em><em>t</em><em>=</em><em>2</em><em>4</em><em> </em><em>mins</em><em> </em><em>to</em><em> </em><em>t</em><em> </em><em>mins</em><em>.</em>
(t -24)= 28
t - 32= 28
t= 32 +28
t= 60
t=
t= 45
*Here, I assume that this is a displacement- time graph, so the distance shown is the distance of the bus from the starting point because technically if it is a distance-time graph, the distance would still increase as the bus travels the 'return journey'.
Thus, distance is decreasing after t=24 and reaches zero at time= t mins so that is the return journey. (because when the bus returns back to starting point, displacement/ distance from starting point= 0km)
Answer:
Step-by-step explanation:
Please refer to the image attached with this answer. Assuming our triangle to be ΔABC and Line AD meeting BC at D.
As we are given that side b = side c
The angle subtended by them ∠B and ∠C must be equal . Let us assume them to be x each . hence
x + x + 52° +31° = 180°
2x + 73° = 180°
2x = 180°- 73°
2x = 107 °
x = 53.5°
Hence in ΔACD
x+ 31°+∠2= 180°
53.5°+31°+ ∠2 = 180°
∠2=180°-84.5°
∠2=95.5°
Also
∠1 + ∠2 = 180°
∠1 + 95.5° = 180°
∠1 = 180°-95.5°
∠1 =84.5°
Now applying Sine rule in ΔABD
Hence we have c as 15.14
as we are given that side c = side b , b=15.14
The properties of any triangle says that the sum of two sides of any triangle is always greater than the third side. Hence
a<b+c
12+2x-6<15.14+15.14
6+2x<30.28
2x<30.28-6
2x<24.28
x<12.14
also side a must be greater than 0
12+2x-6>0
6+2x>0
2x>-6
x>-3
Hence the range of x will be
-3 <x < 12.14
