Answer:
![a = 1.07 m/s^2](https://tex.z-dn.net/?f=a%20%3D%201.07%20m%2Fs%5E2)
Explanation:
As we know that the runner starts from rest position
So here we can say
![v_i = 0](https://tex.z-dn.net/?f=v_i%20%3D%200)
now the distance moved by the runner is given as
![d = 30 m](https://tex.z-dn.net/?f=d%20%3D%2030%20m)
also we know that final speed of the runner will be
![v_f = 8 m/s](https://tex.z-dn.net/?f=v_f%20%3D%208%20m%2Fs)
now we know that
![v_f^2 - v_i^2 = 2 a d](https://tex.z-dn.net/?f=v_f%5E2%20-%20v_i%5E2%20%3D%202%20a%20d)
![8^2 - 0 = 2(a)(30)](https://tex.z-dn.net/?f=8%5E2%20-%200%20%3D%202%28a%29%2830%29)
![a = \frac{64}{60}](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7B64%7D%7B60%7D)
![a = 1.07 m/s^2](https://tex.z-dn.net/?f=a%20%3D%201.07%20m%2Fs%5E2)
Answer:
A system that includes the stone and the earth.
Explanation:
If the system of being dropped from the height of the cliff consists of just the stone alone, then it means that its momentum will certainly undergo changes as it falls freely. However, If the system is now expanded to include not only the stone but also the Earth, then it implies that the momentum of the stone which is in the downward direction will be equal and opposite to the momentum of the Earth in the upwards direction towards the stone. Therefore, the momentum will cancel out and net momentum will be zero.
Answer: D. The force and displacement are in the same direction.
Explanation:
The Work
done by a Force
refers to the release of potential energy from a body that is moved by the application of that force to overcome a resistance along a path with distance
.
Work is a scalar magnitude, and its unit in the International System of Units is the Joule (like energy).
Now, when the applied force is constant and the direction of the force and the direction of the displacement are <u>parallel</u>, the equation to calculate it is:
(1)
When they are not parallel, both directions form an angle, let's call it
. In that case the expression to calculate the Work is:
(2)
When the force and displacement are perpendicular to each other,
and <u>no work is done</u>.
Answer:
I ve done this and its B hope this helps :)
Explanation:
Make sure to think aboutthe question before submitting!
<3
Most geologists accept radiometric dating techniques as valid because radioactive elements decay at a constant and measurable rate.
Answer: Option C
<u>Explanation:</u>
Scientists prefer radioactive dating to carbon dating because it is more accurate in measuring. The analysis depends upon the radioactive decay of radioactive isotopes of any matter in a given rock or soil.
The parent atoms and daughter atoms are compared while studying, and hence age can be calculated easily. Radioactive decay depends upon the given half-life of the atom, which is a constant and is known. So, it would be very easy to calculate the number of progeny atoms and parent atoms and find out their age.