Meselson and Stahl
<u>Explanation:</u>
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The classic experiment that supported the semiconservative model of dna replication was performed by Matthew Meselson and Franklin W. Stahl. In this model, the two strands of DNA unwind from each other, and each acts as a template for synthesis of a new, complementary strand. This results in two DNA molecules with one original strand and one new strand. They used E. coli bacteria as a model system.
Answer:
The block has an acceleration of 
Explanation:
By means of Newton's second law it can be determine the acceleration of the block.
(1)
Where
represents the net force, m is the mass and a is the acceleration.
(2)
The forces present in x are
and
(the friction force):

Notice that
subtracts to
since it is at the opposite direction.

The forces present in y balance each other:

Therefore:
(3)
But
and writing (3) in terms of a it is get:

So the block has an acceleration of
.
It’s D because kinetic energy is the energy of motion
Answer:
6666.67 Newtons
Explanation:
The formula F=ma (force is equal to mass multiplied by acceleration) can be used to calculate the answer to this question.
In this case:
- mass= 0.1mg= 1*10^-7 kg
- velocity= 4.00*10^3 m/s
- time= 6.00*10^-8 s
Using velocity and time, acceleration can be calculated as:
Substituting these values into the formula F=ma, the answer is:
- F= (1*10^-7)kg * (6.667*10^10) m/s²
- F= 6666.67 Newtons of force
Distance is the total length covered = 2m + 3m = 5m
Displacement is his distance from original position.
Displacement = 2m + (-3)m. Representing the 3m walked back as -3.
Displacement = 2m - 3m = -1m.
So his displacement is 1m behind his original starting point.