1. Questions

Physics

A 56.6kg hiker starts at an elevation of 1270m and climbs to the top of a 2660 peak.

(I know the answers to B and C, I just have a question on A)
A) What is the change in the hikers potential energy?

I took PE=mg(h2-h1) and got (56.5)(9.8)(2660-1270)=769643J

When I checked my work with some problems on the net, I was seeing answers as large as mine and others that only used 4 digits (Like 7696J)

Why are they cutting them down, and shouldn't the unit change if they did? If the unit should change... why?

  1. 👍
  2. 👎
  3. 👁
Elisabeth

  1. Your calculation looks good to me, except for the number of significant digits (too many) in the answer.
    You may want to review the other answers on the net to see if
    1. they use different units (hJ, kJ, etc.)
    2. they use scientific notation, like 7696*10²J., thereby trimming on the number of significant digits.

    Also, is the hiker's mass 56.5 or 56.6?

    1. 👍
    2. 👎
    MathMate

  2. Just a typo on my part. The hiker's mass is the same as in my equation: 56.5.

    I just looked over the answers again. Most people answered the same as I did. A few of them put in scientific notation, but not like you did. they put 7.6X10^5 which doesn't make sense to me. I like your notation better. Fits the four digits. One person answered it in kJ, but the answer was only three digits long. I think I am going with the four digit scientific notation. It makes the most sense to me.

    Thank you very much!

    1. 👍
    2. 👎
    Elisabeth

  4. I personally would suggest using powers of 10 that are multiples of three (some call it the engineering notation). This makes for easier interpretation, i.e. thousands, millions, billions, etc.

    So
    769643J
    =769.6*10^3J
    =769.6kJ
    =0.770*10^6J
    etc.

    1. 👍
    2. 👎
    MathMate

Respond to this Question

First Name

Your Response

Similar Questions

  1. Science

    Three people hiked to the top of the hill represented by the following topographic map. Each hiker started at the same elevation but at different locations around the hill. Use this map for questions 4 - 6. (All of them are at a

  2. trigonometry

    the angle of elevation of the top of the tower from the foot of a flagpole is twice the angle of elevation of the top of the flagpole from the foot of the tower. at the point midway between the tower and the flagpole, the angles

  3. Physics

    How much work is done when a mass of 3 kg (weighing 30 N) is lifted vertically through 6 m?. A hiker climbs a hill 300 m high. If she has a mass of 50 kg calculate the work she does in lifting her body to the top of the hill.

  4. Math

    1. A rangers tower is located 44m from a tall tree. From the top of the tower, the angle of elevation to the top of the tree is 28 degrees and the angle of depression to the base is 36 degrees. How tall is the tree? 2. An engineer

  1. physics

    A hiker climbs a hill 300m high.If she weighs 50kg,calculate the work she does in lifting her body to the top of the hill

  2. physics

    A 55 kg hiker starts at an elevation of 1600 m and climbs to the top of a 3400 m peak. (a) What is the hiker's change in potential energy?

  3. math

    A hiker is 400 meters away from the base of the radio tower. The angle of elevation to the top of the tower is 46 degrees . How high is the tower?

  4. 4 grade

    A snail climbs up a wall 20 feet high. Each day the snail climbs 5 feet, but each night it slips backwards 4 feet. How many days will it take for the snail to get to the top of the wall?

  1. AP Physics

    I need someone to review the following questions for my summer assignment and tell me if my answers are right or wrong. Please do it carefully, and the problems I found to be the most trickiest were #2 and #5. (This is is AP

  2. Math Olympiad

    Lara starts at the bottom of a long staircase. She climbs exactly 2/3 of the stairs. Then, she goes back down exactly 1/2 of the way to the bottom. From that spot, she climbs exactly 2/3 of the way to the top. Finally from there,

  3. PHSYICS

    A HIKER SHOUTS TOWARD A VERTICAL CLIFF 685 M AWAY. THE ECHO IS HEARD 4.00 SECONDS LATER. WHAT IS THE SPEED OF SOUND OF THE HIKER'S VOICE IN AIR?

  4. math

    A point is directly below a window. Another point B is 15 m from A and at the same horizontal level. From B angle elevation of the top of the bottom of the window is 300 and the angle elevation of the top of the widow is 350.

You can view more similar questions or ask a new question.