Question
A stone thrown horizontally from a height of 7.8 m hits the ground at a distance of 12.0 m. Calculate the speed of the ball as it hits the ground.
I was able to find the initial speed of the ball, which is 9.52 m/s. However, I'm unsure about whether I need to use this number to get the speed as it hits the ground.
I was able to find the initial speed of the ball, which is 9.52 m/s. However, I'm unsure about whether I need to use this number to get the speed as it hits the ground.
Answers
The speed which which it was thrown is 12.0 m/(fall time) = The fall time is
T = sqrt (2H/g) = 1.262 s
Vox = 12.0/1.262 = 9.51 m/s. Close enough. You WILL need that number to finish the problem. It remains the horizontal component of velocity until it hits the ground.
The vertical component of velocity when it hits the ground is
Vyfinal = sqrt (2gH) = 12.36 m/s
When it hits the ground, the speed is
Vfinal = sqrt[Vox^2 + Vyfinal^2] =?
T = sqrt (2H/g) = 1.262 s
Vox = 12.0/1.262 = 9.51 m/s. Close enough. You WILL need that number to finish the problem. It remains the horizontal component of velocity until it hits the ground.
The vertical component of velocity when it hits the ground is
Vyfinal = sqrt (2gH) = 12.36 m/s
When it hits the ground, the speed is
Vfinal = sqrt[Vox^2 + Vyfinal^2] =?
15.6 m/s. I understand now, thanks a bunch.
Yes, that's great explain. Also, you be able to use suvat formulae in steps to work out time and then vox and then resultant velocity.
Related Questions
A stone thrown horizontally from a height of 6.32 m hits the ground at a distance of 14.30 m. Calcul...
a stone is thrown straight up from a 50m high building and hits the ground at a speed of 37.1m/s. Wh...
A 2.3kg stone is thrown from ground directly upward. the maximum height reached by the stone is 45m....
A stone is thrown from the top of a tower of height 60m with velocity 40m/s at an angle of 30 degree...