Civil Engineering - Applied Mechanics - Discussion

Discussion Forum : Applied Mechanics - Section 1 (Q.No. 3)
3.
At a given instant ship A is travelling at 6 km/h due east and ship B is travelling at 8 km/h due north. The velocity of B relative to A is
7 km/hrs
2 km/hrs
1 km/hrs
10 km/hrs
14 km/hrs.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
22 comments Page 1 of 3.

Gaurav gupta said:   1 decade ago
By using pythagoras theorem;

(8*8) + (6*6) equal to 100 and square root of 100 is 10.

Saurabh said:   1 decade ago
It should be 10. Why it is 14 anyone explain this?

Ankur padalia said:   1 decade ago
Using the pythagoras theorem.

Amol Ashok Lande said:   1 decade ago
(V)x = 6.
(V)y = 8.
Vb/a = (36+64)^1/2.
Vb/a = 10 km/hr.

Saleem khan said:   1 decade ago
Both force are acting on right angle so we will find resultant acc to parallelogram law. R^2 = f1^2 + f2^2 + cos90.

But there is value of cos90 = 0.

ABDUL SALAM ANSARI said:   1 decade ago
Both force are acting on right angle so, we will find resultant according to parallelogram law.

R^2 = f1^2 + f2^2 +2f1*f2*cos90.

But there is value of cos90 = 0.

We know,

f1 = 6km/hr and f2 = 8km/hr.

R^2 = 6^2+8^2+2*6*8*0.

=> R^2 = 36+64.
=> R = (100)^1/2.
=> R = 10km/hr.

CHANDAN KUMAR said:   1 decade ago
The force are acting at right angle so simply you know that find resultant r^2 = p^2+Q^2.

Assume p = 6, q = 8 substitute this values.

r^2 = 6^2+8^2.

r^2 = 36+64.

r^2 = 100.

Now do the square root of 100 is 10.

Thus r = 10km/hr.

A KUMAR said:   1 decade ago
Va = 6i+0j, Vb = 0i+8j.

Vba = Vb-Va.

6i+0j-(0i+8j) = 6i-8j.

Magnitude of Vba = (6^2+8^2)^1/2.

= (100)^1/2.
= 10 mtr/sec.

Usama ahmad said:   1 decade ago
6*6+8*8=100 s of 100=10.

Nitesh jayswal said:   9 years ago
By using Pythagoras theorem:-

8 * 8 + 6 * 6 = 100.
Square root of 100 = 10km/hr.


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