SOLUTION: Please help me on my homework. please correct my solutions and answers because i'm not sure if these are right answers.
1. 2 cars leave the same place at the same time. each car
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1. 2 cars leave the same place at the same time. each car
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Question 175045: Please help me on my homework. please correct my solutions and answers because i'm not sure if these are right answers.
1. 2 cars leave the same place at the same time. each car travels at a speed of 60 kph. one travels in the direction 60 degrees east of north. the other travels in the direction 45 degrees east of south. how far apart are the two cars after 30 minutes?
My solution:
d= distance of two cars after 30 min
sin60=x/60kph sin45=y/60
x=51kph y=42.43kph
d=51.96kph+42.43kph
d=94.39kph
d=94.39 km/1hr x 1 hr/60 min x 30 min
my answer : d= 47.20 km
2. 2 ships leave a big port at the same time. the first ship travels N 30 degrees W at 20 kph. the other heads toward N 15 degrees E at 25 kph. how far apart will they be in 3 hours?
sin30=x/20 kph sin15=y/25
x=10 y=6.47
10 kph + 6.47 kph = 16.47 kph
16.47 km/1 hr x 3 hrs = 49.41 km
3. A regular pentagon is inscribed in a circle whose radius is 18 cm. find the perimeter of the pentagon.
I really don't know how to solve it.
You can put this solution on YOUR website! I'll convert the velocity vectors to distance vectors. Then
I'll find the points on the x-y plane where the end up and use the distance formula
" One travels in the direction 60 degrees east of north."
That's the same as 30 degrees N of E. In a half-hour this car
would have gone 60 km/hr x 1/2 hr = 30 km
The component along the y-direction is
The component along the x-direction is
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" The other travels in the direction 45 degrees east of south."
That's the same as 45 degrees south of east
This car also would have gone 60 km/hr x 1/2 hr = 30 km
The component along the y-direction is
The component along the x-direction is
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Now I have 2 points
(,)
and
(,)
Now I use the distance formula km
