question_answer

At 7 a.m. the angle between the Sun's ray and the ground at a point is\[\text{43 }\!\!{}^\circ\!\!\text{ }\]. What would be the angle at 10 a.m.?

A) \[\text{40 }\!\!{}^\circ\!\!\text{ }\]

B) \[\text{90 }\!\!{}^\circ\!\!\text{ }\]

C) Between \[\text{43 }\!\!{}^\circ\!\!\text{ }\] and \[\text{90 }\!\!{}^\circ\!\!\text{ }\]  

D) Greater than \[\text{90 }\!\!{}^\circ\!\!\text{ }\]

Correct Answer: C

Solution :

Let QP be the sun's ray and RP be the ground. The angle between QP and PR at P is \[\text{43 }\!\!{}^\circ\!\!\text{ }\] at 7 a.m. At 10 a.m., the sun's ray is Q'P. We know that at 12 noon the sun is exactly above our head. So, the sun's ray will be perpendicular to the ground. So, clearly at 10 am, the required angle will be between \[\text{43 }\!\!{}^\circ\!\!\text{ }\] and\[\text{90 }\!\!{}^\circ\!\!\text{ }\].