<span>Since forces are vector quantities, we must indicate direction using positive and negative values. East will be assigned positive and west will be negative. Friction will act as a negative force since it impedes action. To calculate the net force we sum the vector quantities, as follows. Net force equals 50n which is derived by the following calculation: 300n-220n-30n.</span>
The best answer would be the 4th choice. "They help scientists explain concepts that are difficult to observe, this also covers the first answer which helps the scientist to answer complex questions. A scientific model is not used prove scientific laws as they may not always have all the data to prove so, instead it is used to allow them to explain better concepts revolving around science through research and may also allow them to predict results based on the accumulation of data and analyzing the trend of this resulting information.
Answer:
hi here is your answer and this is a very important question.
Explanation:
A lever is a rigid bar with three parts: the fixed point around which the bar pivots is the fulcrum: the effort arm (in-lever arm) is the part of the lever to which force is applied; the resistance arm (out-lever arm) is the part that bears the load to be moved.
The equation we use is mλ=dsinθ for intensity maximas. We are given at the first maximum (m=1), it occurs at 17.8 degrees. Thus we can solve for d by substituting known values into our equation.
(1) (632.8*10^-9m)=dsin(17.8) => d = 2.07*10^-6m
Next we want to find the angle at the second maximum (m=2) so we need to solve for θ.
(2) (632.8*10^-9m) = (2.07*10^-6m)sinθ
θ=37.69 degrees
Hopes this helps!
P.S. I hope this is right. If not sorry in advance.