A 300 kg rocket sits on a launch pad. What is the thrust nee

[j doe]

Homework Statement

A 300 kg rocket sits on a launch pad. What is the thrust needed to obtain a thrust to weight ratio 3:1?

Homework Equations

The Attempt at a Solution

300.0 kg x 9.817 m/s² = 2945.1 N

i know this is not the correct answer, but i have no idea where to start. can someone please help?

 

[BvU]

Hello JD,
what do you think they mean with a thrust to weight ratio ?

 

[j doe]

the amount of acceleration it needs in order to thrust an object with the mass of 300 kg?

 

[Kaura]

I do not have much experience with this sort of equation but I believe that the equation for thrust to weight ratio is T/W where T is the force of the thrust and W is the weight of the given body measured in Newtons hope this helps

 

[j doe]

I do not have much experience with this sort of equation but I believe that the equation for thrust to weight ratio is T/W where T is the force of the thrust and W is the weight of the given body measured in Newtons hope this helps

so based on your equation, would it be 3 / 2945.1 N? that would equal 0.00101864113. what would the units be?

 

[Kaura]

so based on your equation, would it be 3 / 2945.1 N? that would equal 0.00101864113. what would the units be?

I think you would have to find the force of thrust so that T/W would be equivalent to 3/1

 

[j doe]

I think you would have to find the force of thrust so that T/W would be equivalent to 3/1

how do i do that?

 

[SteamKing]

how do i do that?

Do you know what a ratio is?

Here's an example:

The ratio of centimeters to meters is 100 to 1.

You are asked to find the thrust such that a thrust to weight ratio of 3 to 1 is obtained. You have already determined the weight of the rocket.

 

[j doe]

Do you know what a ratio is?

Here's an example:

The ratio of centimeters to meters is 100 to 1.

You are asked to find the thrust such that a thrust to weight ratio of 3 to 1 is obtained. You have already determined the weight of the rocket.

do i multiply 2945.1 by 3? I'm not quite sure how to find the thrust.

 

[SteamKing]

do i multiply 2945.1 by 3? I'm not quite sure how to find the thrust.

weight = mass × acceleration due to gravity

You calculated the weight of the rocket in Post #1 (2945.1 N)

You want the thrust o this rocket to be 3 times its weight.

Therefore, the thrust = ?

 

[j doe]

weight = mass × acceleration due to gravity

You calculated the weight of the rocket in Post #1 (2945.1 N)

You want the thrust o this rocket to be 3 times its weight.

Therefore, the thrust = ?

thrust = 2945.1 N x 3 = 8835.3 N?

 

[Kaura]

thrust = 2945.1 N x 3 = 8835.3 N?

I believe that that is correct

If this is the case then excellent job

 

[SteamKing]

thrust = 2945.1 N x 3 = 8835.3 N?

That looks OK.