 #1
aqryus
 6
 1
 Homework Statement:

A deep space probe of mass 4.55 x10^4kg is travelling at an initial speed of 1.22 x10^4
m/s. The engines of the probe exert a force of magnitude 3.85 x10^5
N over 2.45 x10^8 m. Determine the probes final speed
 Relevant Equations:

W=Ek2Ek1
W=fd
W=(1/2)mv2^2(1/2)mv1^2
First I found work:
W=(3.85x10^5)(2.45x10^8)
W= 9.43x10^13
Then used that for difference of kinetic energy:
9.43x10^13 = (1/2) (4.55x10^4)v2^2  (1/2)(4.55x10^4)(1.22x10^4)^2
9.43x10^13 = (22750)v2^2  3.386x10^12
9.43x10^13 + 3.386x10^12 = (22750)v2^2
9.77x10^13 = 22750v2^2
9.77x10^13/22750 = v^2
squareroot 4.3x10^6 = v
6.55x10^4 = v
But the answer is 1.38x10^4 m/s? I'm not sure where I went wrong. Any help is appreciated
W=(3.85x10^5)(2.45x10^8)
W= 9.43x10^13
Then used that for difference of kinetic energy:
9.43x10^13 = (1/2) (4.55x10^4)v2^2  (1/2)(4.55x10^4)(1.22x10^4)^2
9.43x10^13 = (22750)v2^2  3.386x10^12
9.43x10^13 + 3.386x10^12 = (22750)v2^2
9.77x10^13 = 22750v2^2
9.77x10^13/22750 = v^2
squareroot 4.3x10^6 = v
6.55x10^4 = v
But the answer is 1.38x10^4 m/s? I'm not sure where I went wrong. Any help is appreciated
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