# Physics

Zero, a hypothetical planet, has a mass of 1.0x10^23 kg, a radius of 3.0x10^6 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its surface.
(a) If the probe is launched with an initial kinetic energy of 5.0x10^7 J, what will be its kinetic energy when it is 4.0x10^6 m from the center of Zero?
(b) If the probe is to achieve a maximum distance of 8.0x10^6 m from the center of Zero, with what initial kinetic energy must it be launched from the surface of Zero?

* Physics/Math - drwls, Wednesday, March 7, 2007 at 5:55am

Use the rel;ationship
KE + Potential energy) = constant.

The potential energy at distance R from the center is
-GMm/R
M is the planet's mass and m is the probes.
That means (1/2) mV^2 - GMm/R = constant
Use that fact to compute the unknown kinetic energy in each problem

---------------------

this is what i did..

V = sqrt(2GM/R)
V = sqrt(2(6.67e-11)(1.0e23)/(3.0e6))
V = 2108.7
[..would i use earth's gravity for this question? .. if not.. what should i use for G?]

then..

(1/2) mV^2 - GMm/R = constant
(.5(10)(2108.7)^2 - ((6.67e-11)(1.0e23)(10)/(4.0e6))
111165392.3 - 16675000 = 94490392.3 = 9.4e7

.. what am i doing wrong?

and how would i go about with the 2nd question?

1. 👍 0
2. 👎 0
3. 👁 102

## Similar Questions

1. ### Physics/Math

Ok...I figured out part a but I am having trouble with b. part a was: Zero, a hypothetical planet, has a mass of 1.0x10^23 kg, a radius of 3.0x10^6 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its

asked by Technoboi11 on March 14, 2007

1.Write the number in standard form: 7.1x10^4 A)710 B)7,100 C)71,000 D)710,000*** 2.Write the number in standard form: 5.01x10^-3 A)5,010 B)0.501 C)0.0501 D)0.00501*** 3.Multiply (2.0x10^4)(3.0x10^3)=? A)6.0x10^7*** B)6.0x10^12

3. ### Physics/Math

Ok...I figured out part a but I am having trouble with b. part a was: Zero, a hypothetical planet, has a mass of 1.0x10^23 kg, a radius of 3.0x10^6 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its

asked by Technoboi11 on March 12, 2007
4. ### Re: Physics/Math

Posted by Technoboi11 on Wednesday, March 7, 2007 at 1:09am. Zero, a hypothetical planet, has a mass of 1.0x10^23 kg, a radius of 3.0x10^6 m, and no atmosphere. A 10 kg space probe is to be launched vertically from its surface.

asked by TechnoBoi11 on March 9, 2007
5. ### physics

a 500g balance weight is transported to the surface of planet z where an objects weight is measured to be 5.00N. The radius of the planet is 5.0x10^5m. What is the mass of planet z?

asked by marisa on April 11, 2018
6. ### Chemistry

what is Kc at 25 celsius for the following equilibrium? CH3BH3^+ +H2O CH3NH2 + H3O^+ Kb=4.4x10^-4 I got 4.0x10^4 / 1.0x10^-14 = 4.0x10^-10 (correct)?

asked by Bb on March 22, 2013
7. ### Physics

Astronomers can calculate the mass of a planet by using the orbital parameters of one of its moons. Consider a hypothetical planet, which has a hypothetical moon that orbits the planet in a roughly circular orbit with a radius of

asked by Emily on October 23, 2012
8. ### Physics

Using Coulomb's law to solve: Charge A is +2.0x10^-6C and charge B is +3.0x10^-6C. The two changes are 3 m apart. What is the force between them?Is the force attractive or repulsive? Okay so here's what I have so far

asked by ANONYMOUS on March 28, 2017
9. ### chemistry

if the combustion of oil yields 4.0x10^4 kj/kg what mass of oil must be burned to yield the number of joules in part b? the answer i got in part b was 7.70 x10^11 J and that it right. for this problem i divided the answer i got

asked by MARY :) on November 19, 2010
10. ### chemistry

if the combustion of oil yields 4.0x10^4 kj/kg what mass of oil must be burned to yield the number of joules in part b? the answer i got in part b was 7.70 x10^11 J and that it right. for this problem i divided the answer i got

asked by MARY :) on November 19, 2010

More Similar Questions