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kr73114
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1) A piece of paper is in the shape of a sector of a circle. The radius is 8cm and the angle at the centre is 3pi/4 radians. The straight edges of the sector are placed together so that a cone is formed. Show that the base of the cone has a radius of 3cm. Find the area of theh curved surface of the cone.
2) A plane flying due east at 600km/h at a constant altitude. From an observation point P on the ground the plane is sighted on a bearing of 320o. One minute later the bearing of the plane is 75o and its angle of elevation is 25o. How far has the plane traveled between sightings. Draw a diagram to represent the information given. Show that the altitude h metres of the plane is given by
h= 10000sin50 tan25/sin65 and hence find h. Find correct to the nearest degree the angle of elevation of the plane from P when first sighted.
2) A plane flying due east at 600km/h at a constant altitude. From an observation point P on the ground the plane is sighted on a bearing of 320o. One minute later the bearing of the plane is 75o and its angle of elevation is 25o. How far has the plane traveled between sightings. Draw a diagram to represent the information given. Show that the altitude h metres of the plane is given by
h= 10000sin50 tan25/sin65 and hence find h. Find correct to the nearest degree the angle of elevation of the plane from P when first sighted.
