Question

9. A lemming runs from a point A to a cliff at 4 m/s, jumps over the
edge at B and falls to C at an average speed of 25 m/s. If the total
distance from A to C is 500 m and the time taken for the journey is
41 seconds, find the height BC of the cliff.​

Answer 1

Step-by-step explanation:

let c = height of the cliff

total A to C distance given as 500m

(500-c) = distance from A to B

:

Write a time equation; time = dist/speed

:

Run time + fall time = 41 sec

%28%28500-c%29%29%2F4 + c%2F25 = 41

multiply by 100, clears the denominators,

25(500-c) + 4c = 4100

12500 - 25c + 4c = 4100

-25c + 4c = 4100 - 12500

-21c = -8400

c = -8400/-21

c = 400 meter clif

Answer 2

Answer:

400m

Step-by-step explanation:

A->cliff->B->C

4x+25y=500

(x+y)=41, where x is time spent by lemming to travel distance from A to cliff and y is time for the rest of journey;

x=41-y and 164-4y+25y=500, 21y=336, y=16

the height of BC of the cliff is 25y or 25*16=400 m.

answer: 400 m.

Regards

Timber,

United Kingdom