Advertisements
Advertisements
Question
The weight of a person on planet A is about half that on the earth. He can jump up to 0.4 m in height on the surface of the earth. How high he can jump on planet A?
Solution
The weight of a person on a planet is half that on the earth,
WA = `1/2 "W"_"E"`
or mgA = `1/2 "mg_E"`
or `"g"_A = 1/2 "g"_E`
Now, as the person jumps, gain in potential energy remains the same.
So, mgAhA = mgE hE
∴ `"h"_A = ("g"_"E""h"_"E")/"g"_"A"`
= `("g"_"E" xx 0.4"m")/("g"_E/2)` (Using (I) nd hE = 0.4 m)
= 0.8m
(Using (i) and hE = 0.4 m)
APPEARS IN
RELATED QUESTIONS
Write true or false of the following statement.
In an electric fan, electrical energy changes into the mechanical energy.
Fill in the blank
The S.I.unit of energy is ______
Match the following columns
| COLUMN A | COLUMN B |
| 1. Running water | 1. heat energy |
| 2. Burning | 2. vibrations |
| 3.Energy | 3.atom bomb |
| 4.Sound energy | 4.kinetic energy |
| 5.Nuclear energy | 5.joule |
Select the correct alternatives
The correct statement is
State two factors on which the potential energy of a body at a certain height above the ground depends.
Name the quantity whose unit is :
(a) kilowatt
(b) kilowatt-hour
A cell converts one form of energy into another form. Name the two forms.
Derive the relation between commercial unit of energy (kWh) and SI unit of energy (joule).
Running water possesses ______.
What energy transfer happen in a car engine?
