what is the minimum energy needed to lift 1.0 kg to a height of 200 km and to give it a speed of 8.0 km/s?

(neglect the small decrease of "g" over that distance)

a) 34 KJ

b) 34 TJ

c) 34 MJ

d) 34 J

e) 34 GJ

Printable View

- Jul 28th 2006, 04:08 PMCeliaWhat is the minimum...
what is the minimum energy needed to lift 1.0 kg to a height of 200 km and to give it a speed of 8.0 km/s?

(neglect the small decrease of "g" over that distance)

a) 34 KJ

b) 34 TJ

c) 34 MJ

d) 34 J

e) 34 GJ - Jul 29th 2006, 04:42 AMtopsquarkQuote:

Originally Posted by**Celia**

So:

$\displaystyle mg \Delta h + (1/2)mv^2$

$\displaystyle = (1.0)(9.8)(2 \, x \, 10^5) + (1/2)(1.0)(8.0 \, x \,10^3)^2$

= 33960000 J = 34 x 10^6 J = 34 MJ.

-Dan