From the top of a tower of height $$40$$ m, a ball is projected upwards with a speed of $$20$$ $$ms-l$$ at an angle of elevation of $$30o$$. Then the ratio of the total time taken by the ball to hit the ground to the time taken to ball come at same level as top of tower.

Question

From the top of a tower of height $$40$$ m, a ball is projected upwards with a speed of $$20$$ $$ms-l$$ at an angle of elevation of $$30o$$. Then the ratio of the total time taken by the ball to hit the ground to the time taken to ball come at same level as top of tower.

Infinity Learn · Accepted Answer

If t is the total time taken, then    $$40$$ $$=$$ $$-20$$ $$sin$$ $$300$$ t $$+$$ $$12$$×$$10$$×$$t2or$$ $$40$$ $$=$$ $$-$$ $$10t+5t2or$$ $$5t2-$$ $$10t-40$$ $$=$$ $$0or$$ $$t2-2t-8$$ $$=$$ $$0or$$ $$t2-4t+2t-8$$ $$=$$ $$0or$$ $$t(t-4)+2(t-4$$ $$)$$ $$=$$ $$0or$$ (t+2)(t-4) $$=$$ $$0t$$ $$=$$ $$4$$ s [Negative time is not allowed]T $$=$$ $$2v$$ $$sin$$ θg $$=$$ $$2$$×$$20$$ $$sin$$ $$30010s$$ $$=$$ $$2$$ s∴   tT $$=$$ $$42$$ $$=$$ $$21$$

From the top of a tower of height 40 m, a ball is projected upwards with a speed of 20 ${ms}^{- l}$ at an angle of elevation of $30^{o}$ . Then the ratio of the total time taken by the ball to hit the ground to the time taken to ball come at same level as top of tower.

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material

From the top of a tower of height 40 m, a ball is projected upwards with a speed of 20 ms-l at an angle of elevation of 30o. Then the ratio of the total time taken by the ball to hit the ground to the time taken to ball come at same level as top of tower.

Remember concepts with our Masterclasses.

Ready to Test Your Skills?

free study material

From the top of a tower of height 40 m, a ball is projected upwards with a speed of 20 ${ms}^{- l}$ at an angle of elevation of $30^{o}$ . Then the ratio of the total time taken by the ball to hit the ground to the time taken to ball come at same level as top of tower.