Physics, asked by imaftab, 1 year ago

A ball is projected from top of a tower with the velocity of 5m/s at an angel of 53° to the horizontal. Its speed when it is at a height of 0.45m from the point of projection is?

Answers

Answered by vickeydey
11
suppose the particle takes t' to move 0.45 m.
Then, the particle has no vertical velocity.
So, 0.45=(1/2)×10×t'=>t'=9/100 s.
Also, v(y)=velocity in the y direction=9/10m/s.
v(x)=constant=5×cos(53)=-5m/s.
hence v=√(25+0.81)=5.08m/s.

imaftab: Answer is not correct..
imaftab: correct answer is 4
vickeydey: plssss tell me that if the particle is projected from the building then it will gain a vertical component of velocity
vickeydey: its not correct
Answered by JunaidMirza
50
Time taken to reach 0.45 m
T = Distance / Speed
= 0.45 / (uCos53)
= 0.45 / (5 * 3/5)
= 0.15 seconds

Vertical velocity after 4s
v = u + at
v = uSin53 - gt
v = 5*4/5 - 9.8*0.15
v = 2.53 m/s

Resultant velocity when it reaches a height of 0.45 m is
V = sqrt(v_x^2 + v_y^2)
= sqrt(3^2 + 2.53^2)
≈ 4 m/s

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