For me: WASH OUR HANDS REGULARLY
Answer:
![v = 186.90\,\frac{m}{s}](https://tex.z-dn.net/?f=v%20%3D%20186.90%5C%2C%5Cfrac%7Bm%7D%7Bs%7D)
Explanation:
The motion of ballistic pendulum is modelled by the appropriate use of the Principle of Energy Conservation:
![\frac{1}{2}\cdot (m_{p}+m_{b})\cdot v^{2} = (m_{p}+m_{b})\cdot g \cdot h](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7B2%7D%5Ccdot%20%28m_%7Bp%7D%2Bm_%7Bb%7D%29%5Ccdot%20v%5E%7B2%7D%20%3D%20%28m_%7Bp%7D%2Bm_%7Bb%7D%29%5Ccdot%20g%20%5Ccdot%20h)
The final velocity of the system formed by the ballistic pendulum and the bullet is:
![v = \sqrt{2\cdot g\cdot h}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2%5Ccdot%20g%5Ccdot%20h%7D)
![v = \sqrt{2\cdot (9.807\,\frac{m}{s^{2}} )\cdot (0.031\,m)}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7B2%5Ccdot%20%289.807%5C%2C%5Cfrac%7Bm%7D%7Bs%5E%7B2%7D%7D%20%29%5Ccdot%20%280.031%5C%2Cm%29%7D)
![v\approx 0.78\,\frac{m}{s}](https://tex.z-dn.net/?f=v%5Capprox%200.78%5C%2C%5Cfrac%7Bm%7D%7Bs%7D)
Initial velocity of the bullet can be calculated from the expression derived of the Principle of Momentum:
![(0.0101\,kg)\cdot v = (2.41\,kg + 0.0101\,kg)\cdot (0.78\,\frac{m}{s} )](https://tex.z-dn.net/?f=%280.0101%5C%2Ckg%29%5Ccdot%20v%20%3D%20%282.41%5C%2Ckg%20%2B%200.0101%5C%2Ckg%29%5Ccdot%20%280.78%5C%2C%5Cfrac%7Bm%7D%7Bs%7D%20%29)
![v = 186.90\,\frac{m}{s}](https://tex.z-dn.net/?f=v%20%3D%20186.90%5C%2C%5Cfrac%7Bm%7D%7Bs%7D)
Amount of work done is zero and so power = 0 watts.
<u>Explanation:</u>
Power is the rate at which work is done, or W divided by delta t. Since the barbell is not moving, the weightlifter is not doing work on the barbell.Therefore, if the work done is zero, then the power is also zero.It may seem unusual that the data given in question is versatile i.e. A weightlifter exerts an upward force on a 1000-N barbell and holds it at a height of 1 meter for 2 seconds. But, still the answer is zero watts , this was a tricky question although conceptual basis of question was good! Power is dependent on amount of work done which is further related to displacement and here the net displacement is zero ! Hence, amount of work done is zero and so power = 0 watts.
Answer:
gravitational force
electrostatic force
Explanation:
The forces that balloons may exert on each other can be gravitational pull due to the mass of the balloon membrane and the mass of the gas contained in each. This force is inversely proportional to the square of the radial distance between their center of masses.
The Mutual force of gravitational pull that they exert on each other can be given as:
![F_G=G. \frac{m_1.m_2}{R^2}](https://tex.z-dn.net/?f=F_G%3DG.%20%5Cfrac%7Bm_1.m_2%7D%7BR%5E2%7D)
where:
gravitational constant ![=6.67\times 10^{-11} m^3.kg^{-1}.s^{-2}](https://tex.z-dn.net/?f=%3D6.67%5Ctimes%2010%5E%7B-11%7D%20m%5E3.kg%5E%7B-1%7D.s%5E%7B-2%7D)
are the masses of individual balloons
the radial distance between the center of masses of the balloons.
But when there are charges on the balloons, the electrostatic force comes into act which is governed by Coulomb's law.
Given as:
![F=\frac{1}{4\pi \epsilon_0} \times \frac{q_1.q_2}{R^2}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7B1%7D%7B4%5Cpi%20%5Cepsilon_0%7D%20%5Ctimes%20%5Cfrac%7Bq_1.q_2%7D%7BR%5E2%7D)
where:
![\rm \epsilon_0= permittivity\ of\ free\ space](https://tex.z-dn.net/?f=%5Crm%20%5Cepsilon_0%3D%20permittivity%5C%20of%5C%20free%5C%20space)
are the charges on the individual balloons
R = radial distance between the charges.
Answer:
D: Conducts electrcity poorly
Explanation:
Most conductors are metals, and non- metals are insulators, therefore they dont conduct electricity