Answer:

Explanation:
The strength of the gravitational field at the surface of a planet is given by
(1)
where
G is the gravitational constant
M is the mass of the planet
R is the radius of the planet
For the Earth:

For the unknown planet,

Substituting into the eq.(1), we find the gravitational acceleration of planet X relative to that of the Earth:

And substituting g = 9.8 m/s^2,

1) Size of the image: 2 cm
In order to calculate the size of the image, we can use the following proportion:

where
p = 80 m is the distance of the tree from the pinhole
q = 20 cm = 0.2 m is the distance of the image from the pinhole
= 8 m is the heigth of the object
is the height of the image
By re-arranging the proportion, we find

2) Magnification: 0.0025
The magnification of a camera is given by the ratio between the size of the image and the size of the real object:

so, in this problem we have

Answer:
1) joule
2) 
3) 
Explanation:
1) Luminosity is the <u>amount of light emitted</u> (measured in Joule) by an object in a unit of<u> time</u> (measured in seconds). Hence in SI units luminosity is expressed as joules per second (
), which is equal to Watts (
).
This amount of light emitted is also called radiated electromagnetic power, and when this is measured in relation with time, the result is also called radiant power emitted by a light-emitting object.
Therefore, if we want to calculate luminosity the Joule as a unit will be used.
2) Work
is expressed as force
multiplied by the distane
:
Where force has units of
and distance units of
.
If we input the units we will have:
This is 1Joule (
) in the SI system, which is also equal to 
3) The formula to calculate the percent error is:

Where:
is the experimental value
is the accepted value

This is the percent error
Answer:
Explanation:
a )
If it is totally absorbed pressure is calculated as follows .
Pressure = I / c where I is intensity of light falling .
= 1000 / 3 x 10⁸
= 3.33 x 10⁻⁶ N / m²
b ) weight of tritium atom
= 3 x 1.67 x 10⁻²⁷ kg
acceleration = force / mass
= 3.33x 10⁻⁶ / 3 x 1.67 x 10⁻²⁷
= .6646 x 10²¹ m /s²
= 66.46 x 10¹⁹ m / s²
Then report it and it might be taken down