Answer:
3.42N
Explanation:
*not too sure bc i left my physics notes at school so it might not be 100% accurate :p*
Use the equation: F = (GMm)/(r^2)
F = force of gravity
G = gravitational constant (6.7x10^-11)
M = mass1 (2.5x10^30kg)
m = mass2 (1kg)
r = radius (7000m)
Plug it in: F = ((6.7x10^-11)(2.5x10^30)(1)) / (7000^2)
F = (1.675x10^20) / (4.9x10^7)
F = 3.4183673x10^12
F = 3.42N
Answer:
proof in explanation
Explanation:
First, we will calculate the number of half-lives:

where,
n = no. of half-lives = ?
t = total time passed = 2100 million years
= half-life = 700 million years
Therefore,

Now, we will calculate the number of uranium nuclei left (
):

and the rest of the uranium nuclei will become thorium nuclei (
)

dividing both:

<u>Hence, it is proven that after 2100 million years there are seven times more thorium nuclei than uranium nuclei in the rock.</u>