Need help with some basic questions

[pack60]

can someone help me with some basic questions

 

[NTUENG]

Mind typing your question so that we can help??

 

[pack60]

questions I need help with

When final velocity is larger than initial velocity, then acceleration is what?


What affects the time that a horizontally projected object remains in the air?


What components of projectile are affected by gravity?

 

[berkeman]

What are your thoughts on these questions? What equations are relevant? We can only help you if you show some of your own work on the problems.

 

[pack60]

1st question: I am thinking that acceleration is positive

2nd question: initial vertical velocity and relative projection height

3rd question: the vertical components, but not sure if their are specific vertical components

 

[berkeman]

You got them right.

 

[pack60]

thanks I am new to this stuff and I am trying to figure it out. got time to help on more?

 

[pack60]

when it says the components of vector mechanics, are they just talking about the x and y components? Or the horizontal and vertical compponents?

 

[berkeman]

The components are just the breakdown of the vector in whatever coordinate system you are using at the time. That could be left/right, forward/backward, up/down. Or (x,y,z). Or lots of other possibilities. (x,y,z) is just a little easier to work with compared to left/right, forward/backward, up/down.

 

[pack60]

thanks. next one
A ball is kicked with an initial velocity of 10 m/s at an angle of 30 degrees. Neglecting air resistance, what is the speed of the ball at landing?

Answer: 10 m/s, the ball will slow down on the way up and speed back up on the way down, maxing out at the initial velocity