D subtract the atomic number from the atomic mass
N = A - Z
Answer:
Part a)
the tension force is equal to the weight of the crate
Part b)
tension force is more than the weight of the crate while accelerating upwards
tension force is less than the weight of crate if it is accelerating downwards
Explanation:
Part a)
When large crate is suspended at rest or moving with uniform speed then it is given as

here since speed is constant or it is at rest
so we will have


so the tension force is equal to the weight of the crate
Part b)
Now let say the crate is accelerating upwards
now we can say


so tension force is more than the weight of the crate
Now if the crate is accelerating downwards


so tension force is less than the weight of crate if it is accelerating downwards
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>
Momentum is a product mass and velocity. If a certain object posses a kinetic energy, then it should have a momentum since it is moving which has a velocity. However, if the object is at rest and only has potential energy, then it would not have momentum. So, for the first question the answer would be yes, an object can have energy without having any momentum. For the second question, every object whether it is moving or at rest, possess some energy, potential for an object at rest and kinetic for an object that is moving. Thus, the answer would be no, an object having momentum would always have energy.