Grade 12Mechanics

From the top of a towr of height 40m a ball is projected upward with a speed of 20 m/s at an angle of 30degree to the horizontal . distance from the foot of the tower where the ball hit the ground is 40*b^{½. Here b is an integer. Find b.}

Hansraj Gyanendra Singh Rajawat

10 Years agoGrade 12

2 Answers

Vikas TU

9 Years ago

in x direcn.

x = 20cos30 * t..............(1)

in y direcn.

-40 = 20sin30*t – 0.5gt^2..............(2)

solve the quad. eqn. (2) and substitute in eqn. (1)

to know the x value.

trinabh kohli

7 Years ago

the logic is simple total range would be u x u x sin60/ g + 40tan30 = 102m

now 40 x b^½

^{would be 120}

^{we get b}^1/2 = 3 and hence b = 9

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From the top of a towr of height 40m a ball is projected upward with a speed of 20 m/s at an angle of 30degree to the horizontal . distance from the foot of the tower where the ball hit the ground is 40*b½. Here b is an integer. Find b.

Hansraj Gyanendra Singh Rajawat

2 Answers

Vikas TU

trinabh kohli

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From the top of a towr of height 40m a ball is projected upward with a speed of 20 m/s at an angle of 30degree to the horizontal . distance from the foot of the tower where the ball hit the ground is 40*b^{½. Here b is an integer. Find b.}

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