a mountain railway AB is of length 864m and rises at an angle of 120° to the horizontal. A train is 856m above sea level when it is at A calculate the height above sea level of the train when it reaches B​

9514 1404 393

  1604 m

Step-by-step explanation:

The relevant trig relation is ...

  Sin = Opposite/Hypotenuse

Here, the "opposite" is the elevation of point B above point A, and the "hypotenuse" is the length of the railway. Then the total height of point B is ...

  B = 856 + 864·sin(120°)

  B = 856 +864(√3)/2 = 856 +432√3 ≈ 1604.246

The height of the train at point B is about 1604 m above sea level.

13875138answer:

step-by-step explanation:

use a calculator!

x = central angle apc = measure of minor arc ac

the two angles x and 30 add to 180, so x+30 = 180 and x = 180-30 = 150. the measure of minor arc ac is 150 degrees.

what we need to do from here is find the circumference and then multiply it by x/360 since there are 360 degrees in a circle. in this case, x = 150, so x/360 = 150/360 = 15/36 = 5/12. the shortest distance along the curve from a to c is 5/12 of the distance around the entire circle (aka circumference)

c = circumference

c = pi*d

c = pi*24

c = 24pi

now multiply this by 5/12 to get

distance along minor arc ac = (5/12)*(circumference)

distance along minor arc ac = (5/12)*(24pi)

distance along minor arc ac = 10pi

the formula you can use is

l = (x/360)*pi*d

with

l = length of minor arc

x = central angle

d = diameter

which essentially is the steps we took though a bit differently.