Hey All, can u guys please help me out?? having trouble solving these.
worked solutions will be great
1. Two families traveling on holiday drive along roads that intersect at right angles. One family is initially 230km from the intersection and drives towards the intersection at an average of 65kmh^(-1). The other family is initially 125km from the intersection and travels towards it at an average of 80kmh^(-1).
a) show that their distance apart is given by d^2= 10625t^2 -49000t=68525
b) hence find how long it will take them to reach their minimum distance apart.
c) find their minimum distance
please draw the diagram (it would help me a lot )
answer
b)2.3h
c)109.7km
2. A farmer want to fence a rectangular paddock and a square paddock with a combined area of 5000m^2. If the length of the rectangular paddock is to be 3 times the size of its breadth
a) find the dimensions of the paddocks that give the largest perimeter
b) calculate the cost of fencing the paddocks, at $19.95
answer
a)square 46.3m x 46.3m , rectangle 30.9m x 92.7 m
b) $8626.38
3. A chemical reaction causes the amount of hydrogen to be reduces at a rate proportional to the amount of hydrogen present at any one time. If the amount of hydrogen is given by the formula A= A0e^(-kt), and 800ml reduces to 650ml after 3 minutes, find
a) the amount of hydrogen after 1 hour
b) how long it will take for the hydrogen to reduce to 100ml
answer
a)12.6ml
b)30min
worked solutions will be great
1. Two families traveling on holiday drive along roads that intersect at right angles. One family is initially 230km from the intersection and drives towards the intersection at an average of 65kmh^(-1). The other family is initially 125km from the intersection and travels towards it at an average of 80kmh^(-1).
a) show that their distance apart is given by d^2= 10625t^2 -49000t=68525
b) hence find how long it will take them to reach their minimum distance apart.
c) find their minimum distance
please draw the diagram (it would help me a lot )
answer
b)2.3h
c)109.7km
2. A farmer want to fence a rectangular paddock and a square paddock with a combined area of 5000m^2. If the length of the rectangular paddock is to be 3 times the size of its breadth
a) find the dimensions of the paddocks that give the largest perimeter
b) calculate the cost of fencing the paddocks, at $19.95
answer
a)square 46.3m x 46.3m , rectangle 30.9m x 92.7 m
b) $8626.38
3. A chemical reaction causes the amount of hydrogen to be reduces at a rate proportional to the amount of hydrogen present at any one time. If the amount of hydrogen is given by the formula A= A0e^(-kt), and 800ml reduces to 650ml after 3 minutes, find
a) the amount of hydrogen after 1 hour
b) how long it will take for the hydrogen to reduce to 100ml
answer
a)12.6ml
b)30min
