Recent content by jysim

Homework Statement A cannon is fired at an angle of 30 degrees above the horizontal from a cliff that is 20m above a flat river bottom. What is the initial speed of the projectile if it is found to land 40m from the base of the cliff? Homework Equations g = 9.8ms^-2 Vi = initial...

What I got so far was Vi cos 30t = 40 Is the total vertical distance merely 20m since the vertical displacement of the cannonball during the parabolic trajectory is 0? (Since it goes up and down the same distance?) - pardon my bad english lol! Is the "t" in the Vi cos 30t = 40 equation the...

The speed is not provided in the question.

Homework Statement A cannon is fired at an angle of 30 degrees above the horizontal from a cliff that is 20m above a flat river bottom. What is the initial speed of the projectile if it is found to land 40m from the base of the cliff? Please provide me with relevant explanations as well...

Homework Statement A ball is shot from a cannon on a hill that is 1.93m high and lands 17.34m away after 1/586s. What was the initial velociy of the ball? I would really appreciate if you can provide explanation as well! Thanks!

Thanks andresodonez and AlephZero for clearing things up for me regarding the Earth and Moon issue :) However, I still don't quite comprehend Newton's Third Law. Say I push a block on the floor, when I push the block with my hand, there is a reaction force by the block on my hand. But why...

I'm just a humble human being here, so if my question comes across as stupid, please forgive me! :) Newton's Third Law of Motion states that for every action there is an equal (in magnitude) but opposite (in direction) reaction. One of my A-level revision guidebooks state that the attraction...