Answer:
Explanation:
Since the block is at rest in an elevated position, we can assume that it only has potential energy.
U=mgh is the formula for potential energy where U=potential energy, m= mass, g=acceleration due to gravity, and h=height.
Plug in known variables....
U=4kg*9.8m/s^2*20m
U=784 joules of potential energy or letter A.
Answer:
B. Resistivity
Explanation:
Resistance offered by a substance of unit area per unit length.
The velocity of the ball when it reaches the ground is equal to B. 68.6 m/s. This value was obtained from the formula Vf = Vi + at. Vf is the final velocity. Vi is the initial velocity. The acceleration is "a", while the time of travel is "t". The solution is:
<span>Vf = Vi + at
</span>Vf = 0 + (-9.8 m/s^2) (7 s)
Vf = -68.6 m/s
The negative sign denotes the direction of the ball.
Answer:
FB = 0.187 N
Explanation:
To find the magnetic force FB in the wire you use the following formula:
the angle between B and L is given by:
Due to B depends on "y" you take into account the contribution of each element dy of the wire to the magnitude of the magnetic force. Thus, you have to integrate the following expression:
![|\vec{F_B}|=Isin\theta\int_0^{0.25}B(y)dy=Isin\theta\int_0^{0.25}(0.5y)dy\\\\|\vec{F_B}|=(2.0*10^{-3}A)(sin36.86\°)(0.5T)[\frac{0.25^2}{2}m]=0.187\ N](https://tex.z-dn.net/?f=%7C%5Cvec%7BF_B%7D%7C%3DIsin%5Ctheta%5Cint_0%5E%7B0.25%7DB%28y%29dy%3DIsin%5Ctheta%5Cint_0%5E%7B0.25%7D%280.5y%29dy%5C%5C%5C%5C%7C%5Cvec%7BF_B%7D%7C%3D%282.0%2A10%5E%7B-3%7DA%29%28sin36.86%5C%C2%B0%29%280.5T%29%5B%5Cfrac%7B0.25%5E2%7D%7B2%7Dm%5D%3D0.187%5C%20N)
hence, the magnitude of the magnetic force is 0.187N
Answer:
A: used has four times the tensile strength of steel and the timber frame, incorporating
Explanation:
Option A is correct because it conveys the correct message intended by the statement and has no grammatical errors.
Option B is wrong because to say "has four times the tensile strength of steel has" is just grammatically and idiomatically wrong as has is used twice in the sentence.
Option C is wrong because the statement that has to do with the flexibility of the timber's frame is more like a separate fact and does not fall under the scope of trying to further explain a fact.
Option D is wrong because it has the same problem in Option C. The comma that is placed after "steel" breaks the sentence and hence does not provide a good understanding of why the building can withstand earthquakes.
Option E is grammatically wrong for using does in the sentence "has four times the tensile strength steel does"
