Question

A satelite is orbiting the Earth. In order to boost it to a higher orbit, the controllers need to increase its velocity by 200m/s(W). If the firing thrusters can provide an acceleration of 2.5m/s^2 (W), how long must they be fired in order to boost the satellite's orbit. Show full work.

Answer 1

Any ideas on how to approach this?

Answer 2

use the knemstics equations.. its a motion question.

Answer 3

*knematics

Answer 4

Yep. Give it a shot.

Answer 5

but i tried amd didnt get it so i was wondering if u could help.

Answer 6

Alright, first you need to identify which equation you'll need to use. Which quantities do you know, and which are you trying to find?

Answer 7

The knowns are v=200 m/s and a=2.5 and i need to find time

Answer 8

That's right. Now do we have any kinematics equations that use only velocity, acceleration, and time?

Answer 9

yup but v2 is not given.. we need 3 knowns in order to solve but this one has only 2 knowns..so thats why i dont know what to do!

Answer 10

Really we aren't looking at an absolute velocity are we? We are looking at the change in velocity. We know that the change in velocity is:\[\Delta v=v_f-v_i=200\frac{m}{s}\]Does that help?

Answer 11

no bc we dont have both Vs tho

Answer 12

do u know how to do this?

Answer 13

This is the equation we're looking at, right?

\[v_f=v_i+at\]

Answer 14

yeah

Answer 15

use the kinematic equations!!!!

Answer 16

With a little rearrangement, it becomes:\[v_f-v_i=at\]And we know that, a change in velocity is defined as:\[\Delta v = v_f-v_i\]We can plug this into our first equation to get:\[\Delta v = at \rightarrow t=\frac{\Delta v}{a}\]

Answer 17

When you're working with kinematics, you'll often be able to combine two quantities by some other definition. It is true that we are looking at a velocity of 200 m/s in this question.

However, this is a CHANGE in velocity, not an absolute velocity. The satellite could initially be going 1000 m/s, but requires an ADDITIONAL 200 m/s to stay in orbit. Be sure to be able to differentiate between absolute velocities and relative velocities.

Answer 18

SO whats the answer? I mean I know this info but i dont know how put it together and get final answer

Answer 19

You'll be using this equation directly:\[t=\frac{\Delta v}{a}\]which was derived from two posts above. I trust you can plug in two quantities and calculate.

Answer 20

oh right! Got it! Thank you!

Answer 21

80 seconds

Answer 22

Can u help me with this one as well

Answer 23

If you've got a different question, go ahead and post it in a new question. (:

Answer 24

alright thank u! :')