CSSA Solution Error? (1 Viewer)

[someth1ng]

Given that acceleration due to gravity is:
Earth: 9.8ms-2
Mars: 3.7ms-2

A person stood on scales that were designed for Earth whilst on Mars. The scale gave a reading of 50kg. What is the actual mass of the person?

a. 132.4kg
b. 50kg
c. 18.9kg
d. 490N

The answer I gave was A, 132.4kg, and seems to be correct.

B would not be correct since a scale measures your mass on Earth can be influenced if you changed the value of g. The mass you measure is based on your weight on Earth.
C is not correct since Earth should definitely measure mass/weight has higher than on Mars.
D is not mass.

My reasoning:
50kg on Earth measure means
W=mg
W=50*9.8
W=490N is needed for 50kg reading.

On Mars
W=mg
490=m*3.7
m=132.4kg true mass is needed to give a reading of 50kg.

Am I correct?

 

[4025808]

What was the answer set by the CSSA?

 

[BL3H]

Yep. That's the way I would've done it. Seems pretty straight forward.

 

[someth1ng]

The CSSA answers said it was B.

 

[Leffife]

The answer should definitely be (A).

(B) just isn't right...

If you are still in doubt, just ask your teacher and he/she will definitely say (A)

 

[xamineO]

My friend said A aswell, not sure why though.

 

[Chowder_Head]

B is definately correct.

 

[Chowder_Head]

My friend said A aswell, not sure why though.

Because he is an idiot and he is wrong?

 

[Leffife]

xamineO, you can just ignore Chowder_Head. Seriously man, stop trolling. Try to get a good life if you can. I rest my case.

 

[zeebobDD]

ins't the mass the same anywhere? hence B

 

[SpiralFlex]

ins't the mass the same anywhere? hence B

.

 

[Timske]

lol

 

[wilsondw]

Given that acceleration due to gravity is:
Earth: 9.8ms-2
Mars: 3.7ms-2

A person stood on scales that were designed for Earth whilst on Mars. The scale gave a reading of 50kg. What is the actual mass of the person?

a. 132.4kg
b. 50kg
c. 18.9kg
d. 490N

The answer I gave was A, 132.4kg, and seems to be correct.

B would not be correct since a scale measures your mass on Earth can be influenced if you changed the value of g. The mass you measure is based on your weight on Earth.
C is not correct since Earth should definitely measure mass/weight has higher than on Mars.
D is not mass.

My reasoning:
50kg on Earth measure means
W=mg
W=50*9.8
W=490N is needed for 50kg reading.

On Mars
W=mg
490=m*3.7
m=132.4kg true mass is needed to give a reading of 50kg.

Am I correct?

Umm...well i dun really do physics so i cant really say but i assume the m is mass and you just multiplied the mass with gravity to get the weight...so wouldnt your mass be 50kg?

 

[Leffife]

Oh not good.... yup the answer is (B). Mass is independent, and isn't influenced by gravity.

 

[Timske]

A person stood on scales that were designed for Earth whilst on Mars

 

[Deliriously]

The scales' that are used to measure mass on Earth are designed to take into account its 9.8m/s gravitation acceleration right?
so it would show a different reading on Mars as the mass is subjected to a different gravitational acceleration but the scales is still set to account for Earth's gravitational acceleration.
I'm going with A.

 

[someth1ng]

Alright, the general consensus is that the correct answer is A, so I'll assume that A is correct.