din't remember the exact ques ...
10th floor of a skyscraper is 2 inches swayed. If the top floor is swayed more than 1 foot(12 inches), structure becomes unstable. What can be the height of the building??
ques was in 8th june exam

• ans- 20 floors..
  
  10th floor of the skyscraper is 2 inches swayed...so, if the top floor of the skyscraper tilt 10 inches more then the structure becomes unstable....now draw a straight line from 10th floor to imaginary top floor vertically..now, if the skyscraper need to be unstable, it might have to make an angle more than 45 degree from the point of 10th floor...if we draw the angle and join it , we will get a triangle of base of 10 inches, let the height of 10 th floor to top floor is x....so,
  tan 45 = x/10
  x = 10..
  the height of the building would be, (10+10)=20 floors....
• 10 years agoHelpfull: Yes(15) No(0)
• shivani, i have assumed that it would have created an angle of 45 degree... .if u want to make something unstable, a glass on ur table, move it about 30 degree and free ur hands, the glass would not drop...make the glass move with a angle of 55 or 60 degree i mean more than 45 degree, it would fall surely...besides, without presuming this angle the question seems irrelevant...now, u tell me, am i right logically assuming this angle???
• 10 years agoHelpfull: Yes(4) No(0)
• anjali, draw a line horizontally from the top floor, if we consider 45 degree as the angle after which the skyscraper would be unstable,then draw a line through that 45 degree... let intersect those two lines...it will form a triangle...from the top view, the base would be 10 inches...10 th floor is already swayed by 2 inches.....so, its simple 12-2=10...
• 10 years agoHelpfull: Yes(2) No(0)
• how u got the angle as 45 degree ?? why it cant be less or more than 45 ?
• 10 years agoHelpfull: Yes(1) No(0)
• how the base become 10inches??????
• 10 years agoHelpfull: Yes(1) No(0)