Answer:
Both A and D
Explanation:
Vector magnintude contains both speed and direction and so do these answer choices of 15km and 30m/s
Answer:
c) ![4.2*10^{-5}C](https://tex.z-dn.net/?f=4.2%2A10%5E%7B-5%7DC)
Explanation:
Coulomb's law says that the force exerted between two charges is inversely proportional to the square of distance between them, and is given by the expression:
![F=\frac{kq_{1}q_{2}}{r^{2}}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7Bkq_%7B1%7Dq_%7B2%7D%7D%7Br%5E%7B2%7D%7D)
where k is a proportionality constant with the value ![k=9*10^{9}\frac{Nm^{2}}{C^{2}}](https://tex.z-dn.net/?f=k%3D9%2A10%5E%7B9%7D%5Cfrac%7BNm%5E%7B2%7D%7D%7BC%5E%7B2%7D%7D)
In this case
, so we have:
![F=\frac{kq^{2}}{r^{2}}](https://tex.z-dn.net/?f=F%3D%5Cfrac%7Bkq%5E%7B2%7D%7D%7Br%5E%7B2%7D%7D)
Solving the equation for q, we have:
![kq^{2}=Fr^{2}](https://tex.z-dn.net/?f=kq%5E%7B2%7D%3DFr%5E%7B2%7D)
![q^{2}=\frac{Fr^{2}}{k}](https://tex.z-dn.net/?f=q%5E%7B2%7D%3D%5Cfrac%7BFr%5E%7B2%7D%7D%7Bk%7D)
![q=\sqrt{\frac{Fr^{2}}{k}}](https://tex.z-dn.net/?f=q%3D%5Csqrt%7B%5Cfrac%7BFr%5E%7B2%7D%7D%7Bk%7D%7D)
Replacing the given values:
![q=\sqrt{\frac{4.0N*(2.0m)^{2}}{9*10^{-9}\frac{Nm^{2}}{C^{2}}}}](https://tex.z-dn.net/?f=q%3D%5Csqrt%7B%5Cfrac%7B4.0N%2A%282.0m%29%5E%7B2%7D%7D%7B9%2A10%5E%7B-9%7D%5Cfrac%7BNm%5E%7B2%7D%7D%7BC%5E%7B2%7D%7D%7D%7D)
![q=4.2*10^{-5}C](https://tex.z-dn.net/?f=q%3D4.2%2A10%5E%7B-5%7DC)
Answer:
Under normal conditions, a magnetic material like iron doesn't behave like a magnet because the domains don't have a preferred direction of alignment. On the other hand, the domains of a magnet (or a magnetized iron) are all aligned in s specific direction.
Answer:
1020g
Explanation:
Volume of can=![1100cm^3=1100\times 10^{-6}m^3](https://tex.z-dn.net/?f=1100cm%5E3%3D1100%5Ctimes%2010%5E%7B-6%7Dm%5E3)
![1cm^3=10^{-6}m^3](https://tex.z-dn.net/?f=1cm%5E3%3D10%5E%7B-6%7Dm%5E3)
Mass of can=80g=![\frac{80}{1000}=0.08kg](https://tex.z-dn.net/?f=%5Cfrac%7B80%7D%7B1000%7D%3D0.08kg)
1Kg=1000g
Density of lead=![11.4g/cm^3=11.4\times 10^{3}=11400kg/m^3](https://tex.z-dn.net/?f=11.4g%2Fcm%5E3%3D11.4%5Ctimes%2010%5E%7B3%7D%3D11400kg%2Fm%5E3)
By using ![1g/cm^3=10^3kg/m^3](https://tex.z-dn.net/?f=1g%2Fcm%5E3%3D10%5E3kg%2Fm%5E3)
We have to find the mass of lead which shot can it carry without sinking in water.
Before sinking the can and lead inside it they are floating in the water.
Buoyancy force =![F_b=Weight of can+weight of lead](https://tex.z-dn.net/?f=F_b%3DWeight%20of%20can%2Bweight%20of%20lead)
![\rho_wV_cg=m_cg+m_lg](https://tex.z-dn.net/?f=%5Crho_wV_cg%3Dm_cg%2Bm_lg)
Where
Density of water
Mass of can
Mass of lead
Volume of can
Substitute the values then we get
![1000\times 1100\times 10^{-6}=0.08+m_l](https://tex.z-dn.net/?f=1000%5Ctimes%201100%5Ctimes%2010%5E%7B-6%7D%3D0.08%2Bm_l)
![1.1-0.08=m_l](https://tex.z-dn.net/?f=1.1-0.08%3Dm_l)
![m_l=1.02 kg=1.02\times 1000=1020g](https://tex.z-dn.net/?f=m_l%3D1.02%20kg%3D1.02%5Ctimes%201000%3D1020g)
![1 kg=1000g](https://tex.z-dn.net/?f=1%20kg%3D1000g)
Hence, 1020 grams of lead shot can it carry without sinking water.
In a surface wave (like water) the water goes up and down, but the wave travels across (parallel to) the surface.