Answer:
The correct option is;
A. honk your horn if you cannot see at least 200 ft ahead
Explanation:
According the California Driver Handbook on Safe Driving Practices, it is required of the driver driving on a narrow mountain road without clear visualization of what is 200 ft ahead of her or him to honk the horn of the vehicle.
The sounding of the horn will alert those ahead of the driver of the possible danger due to her or his oncoming vehicle so that they (those ahead of the driver's oncoming vehicle) can react appropriately.
#1
When rocket is launched from the moon then there will be two forces on the rocket
1. Due to ejected gases the reaction force on rocket in forward direction
2. due to gravitational attraction of moon
So here we need to draw two arrow on its FBD in which first arrow is in the direction of motion of rocket which will be the reaction force on it while other arrow is opposite to its motion which is due to gravitational attraction force.
So answer would be TWO
#2
When crate is placed on the floor then in order to lift the crate upwards we always need an external force that will counter balance the normal force of crate.
Which mean if we make the normal force to be zero then crate will lift upwards and in order to make it zero we need to apply same force as that of normal force
So here the normal force is given as 150 N so we also need to apply 150 N force in order to lift it upwards
#3
If a person lift a box upwards by some force then we can say by force balance
Force applied by person + Normal force = Weight of the box
![F_{app} + F_n = mg](https://tex.z-dn.net/?f=F_%7Bapp%7D%20%2B%20F_n%20%3D%20mg)
we will plug in all values in it
![F_{app} + 150 = 30 * 10](https://tex.z-dn.net/?f=F_%7Bapp%7D%20%2B%20150%20%3D%2030%20%2A%2010)
![F_{app} = 300 - 150](https://tex.z-dn.net/?f=F_%7Bapp%7D%20%3D%20300%20-%20150)
![F_{app} = 150 N](https://tex.z-dn.net/?f=F_%7Bapp%7D%20%3D%20150%20N)
So we applied 150 N force on it
#4
In all cases we need to use force balance
like in case 3
![T + T = W](https://tex.z-dn.net/?f=T%20%2B%20T%20%3D%20W)
![2T = W](https://tex.z-dn.net/?f=2T%20%3D%20W)
![T = \frac{W}{2}](https://tex.z-dn.net/?f=T%20%3D%20%5Cfrac%7BW%7D%7B2%7D)
so here in 3rd case tension is half of the weight
which will be the least tension in all cases
so answer is CASE 3
In the form of an ion, Al 3+, It will lose 3 electrons
From the calculation, the wavelength of the waves is about 264 nm and belongs to the ultraviolet spectrum.
<h3>What is photoelectric effect?</h3>
The term photoelectric effect can be used to describe the loss of electron from the surface of a metal. Given that; KE = E - W, where;
KE = kinetic energy of the emitted photoelectron
E = energy of the photon
W = work function of the metal
![2= E - 2.71\\E = 2 + 2.71\\E = 4.71ev or 7.5 * 10^-19 J](https://tex.z-dn.net/?f=2%3D%20E%20-%202.71%5C%5CE%20%3D%202%20%2B%202.71%5C%5CE%20%3D%204.71ev%20or%207.5%20%2A%2010%5E-19%20J)
λ= hc/E
λ= ![6.6 * 10^-34 * 3 * 10^8/7.5 * 10^-19](https://tex.z-dn.net/?f=6.6%20%2A%2010%5E-34%20%2A%203%20%2A%2010%5E8%2F7.5%20%2A%2010%5E-19)
λ=
or 264 nm
Learn more about wavelength:brainly.com/question/13533093
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