Answer:
<h2>Part a)</h2><h2>Momentum transferred by the ball</h2><h2>
![\Delta P = 157.95 kg m/s](https://tex.z-dn.net/?f=%5CDelta%20P%20%3D%20157.95%20kg%20m%2Fs)
</h2><h2>Part b)</h2><h2>Change in the velocity of the ball is</h2><h2>
![\Delta v = 2.64 \times 10^{-23} m/s](https://tex.z-dn.net/?f=%5CDelta%20v%20%3D%202.64%20%5Ctimes%2010%5E%7B-23%7D%20m%2Fs)
</h2>
Explanation:
Velocity of the stone just before it will strike the Earth is given as
![v = \sqrt{2gh}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2gh%7D)
so we will have
![v = \sqrt{2(9.81)(30)}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2%289.81%29%2830%29%7D)
![v = 24.3 m/s](https://tex.z-dn.net/?f=v%20%3D%2024.3%20m%2Fs)
Now by momentum conservation
![m_1v_i = (m_1 + m_2) v_f](https://tex.z-dn.net/?f=m_1v_i%20%3D%20%28m_1%20%2B%20m_2%29%20v_f)
![6.50(24.3) = (6.50 + 5.972 \times 10^{24})v](https://tex.z-dn.net/?f=6.50%2824.3%29%20%3D%20%286.50%20%2B%205.972%20%5Ctimes%2010%5E%7B24%7D%29v)
![v = 2.64 \times 10^{-23} m/s](https://tex.z-dn.net/?f=v%20%3D%202.64%20%5Ctimes%2010%5E%7B-23%7D%20m%2Fs)
Part a)
Momentum transferred by the stone is given as
![\Delta P = 6.50(24.3 - 2.64 \times 10^{-23})](https://tex.z-dn.net/?f=%5CDelta%20P%20%3D%206.50%2824.3%20-%202.64%20%5Ctimes%2010%5E%7B-23%7D%29)
![\Delta P = 157.95 kg m/s](https://tex.z-dn.net/?f=%5CDelta%20P%20%3D%20157.95%20kg%20m%2Fs)
Part b)
Change in velocity of Earth
![\Delta v = 2.64 \times 10^{-23} - 0](https://tex.z-dn.net/?f=%5CDelta%20v%20%3D%202.64%20%5Ctimes%2010%5E%7B-23%7D%20-%200)
![\Delta v = 2.64 \times 10^{-23} m/s](https://tex.z-dn.net/?f=%5CDelta%20v%20%3D%202.64%20%5Ctimes%2010%5E%7B-23%7D%20m%2Fs)
Answer:
The melting point of indium is 157.436 degrees Celsius.
Explanation:
The resistance of the platinum wire, R1 = 2
The temperature at R1 is, T1 = 20 degrees Celsius.
The increased resistance, R2 = 3.072
Let the temperature at 3.072 = T2
Now find the temperature at which the indium starts melting.
We know that α = ( R2 - R1 ) / [ R1 × ( T2 - T1 ) ]
Given, α = 3.9 x 10^-3/ degrees Celsius.
T2- T1 = ( R2 - R1 ) / R1 α
T2 – T1 = (3.072 – 2) / (2 × 3.9 x 10^-3)
T2 – T1 = 137.436
T2 = T1 + 137.436
T2 = 20 + 137.436
T2 = 157.436 degree Celsius
Answer:
D. Both occur between objects independently whether they are in contact or not.
Explanation:
- The gravitational force is a force that is exerted between two (or more) objects having mass. This force is always attractive and its magnitude is given by
![F=G\frac{m_1 m_2}{r^2}](https://tex.z-dn.net/?f=F%3DG%5Cfrac%7Bm_1%20m_2%7D%7Br%5E2%7D)
where G is the gravitational constant, m1 and m2 are the two masses, and r is the distance between the two masses.
- The electrical force is a force that is exerted between two (or more) objects having electrical charge. It can be either attractive or repulsive, depending on the sign of the two charges, and its magnitude is given by
![F=k\frac{q_1 q_2}{r^2}](https://tex.z-dn.net/?f=F%3Dk%5Cfrac%7Bq_1%20q_2%7D%7Br%5E2%7D)
where k is the Coulomb's constant, q1 and q2 are the two charges, and r the distance between the two charges.
Looking at both formulas, we see that the two forces are present even when the two objects are not in contact with each other (in fact, r can assume any value in the formula). They are said to be non-contact forces. Therefore, the correct option is
D. Both occur between objects independently whether they are in contact or not.
Answer: Option A: The number of trees sampled.
The accuracy can be understood as how close is the measured value to the true value. The aim is to monitor the population size of the insect pest in a 50 square kilometer. Random trees are selected, and number of eggs and larvae are counted. So, the measured value would be closer to actual value when the number of trees sampled are increased. More the number of trees sampled, less would be the chances of error and the accuracy of the estimate would increase.
The planetary wind belts in the troposphere are primarily caused by the Earth's rotation and the unequal heating of Earth's surface.
Planetary wind belts are vast movements and they are driven by the circulation of air. The Sun's heat causes the winds around the world. It heats the tropical zone primarily than the polar regions because the sun's rays are more direct at the equator.