Mechanics: A man throws a tennis ball into the air so that, at the instant....

cake91

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Hello I was hoping someone could helpme with this problem:

A man throws a tennis ball into the airso that, at the istant when the ball leaves his hand the ball is 2m above the ground and is moving veritcally upwards with 9 m/s^-1
The motion of the ball is modelled as that of a particle movingfreely under gravity and the acceleration due to gravity is modelled as being of constant magnitude of 10 m/s^-1
The ball hits the ground T seconds after leaving the mans hand
Using the model find the value of T

I dont understand what they mean exactly by "modelled as that of a particle moving freely under gravity" and how do I go about solving this.
 
Hello I was hoping someone could helpme with this problem:

A man throws a tennis ball into the airso that, at the istant when the ball leaves his hand the ball is 2m above the ground and is moving veritcally upwards with 9 m/s^-1
The motion of the ball is modelled as that of a particle movingfreely under gravity and the acceleration due to gravity is modelled as being of constant magnitude of 10 m/s^-1
The ball hits the ground T seconds after leaving the mans hand
Using the model find the value of T

I dont understand what they mean exactly by "modelled as that of a particle moving freely under gravity" and how do I go about solving this.

m/s^-1 -- Are you SURE about this notation?

You should have a standard setup for this sort of thing. It just means:

\(\displaystyle x(t) = ½gt^{2} + v_{0}t + h_{0}\)

x(t) is the vertical position of the ball above the ground at t seconds after being thrown.
g is the acceleration due to gravity. You must be told this value. Usually 32 feet/s^2 or 9.8 meters/s^2. Pick the right one.
\(\displaystyle v_{0}\) is the initial velocity = 9 m/s
\(\displaystyle h_{0}\) is the initial position = 2 m
 
Hello I was hoping someone could helpme with this problem:

A man throws a tennis ball into the airso that, at the istant when the ball leaves his hand the ball is 2m above the ground and is moving veritcally upwards with 9 m/s^-1
The motion of the ball is modelled as that of a particle movingfreely under gravity and the acceleration due to gravity is modelled as being of constant magnitude of 10 m/s^-1
The ball hits the ground T seconds after leaving the mans hand
Using the model find the value of T

I dont understand what they mean exactly by "modelled as that of a particle moving freely under gravity" and how do I go about solving this.

"modelled as that of a particle moving freely under gravity"
means you ignore the drag on the particle by the air.
 
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