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if A vector travels 3ms -1 and B vector travels 4ms -1 Find | R | after an minute? if their direction between A and B is 76 degree.

if A vector travels 3ms-1 and B vector travels 4ms-1  Find |R| after an minute? if their direction between A and B is 76 degree.

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Grade:8

2 Answers

Arun Kumar IIT Delhi
askIITians Faculty 256 Points
9 years ago
Hello
lets assume
a=3i
b=4cos76i+4sin76j
so
a+b=(3+4cos76)i+4sin76
for position vector just mulitply by 60
Thanks & Regards
Arun Kumar
Btech, IIT Delhi
Askiitians Faculty
Sumit Majumdar IIT Delhi
askIITians Faculty 137 Points
9 years ago
Solution:
The formula for finding the resultant would be given by:
\left | R \right |^{2}=\left | A \right |^{2}+\left | B \right |^{2}-2\left | A \right |\left | B \right |cos\Theta
This results into:
\left | R \right |=\sqrt{3^{2}+4^{2}-2\times 3\times 4\times cos\left ( 76^{\circ} \right )}
Hence the answer is 4.38 m in 1 sec.
So, in 1 min, the distance covered would be equal to 262.86 m.
Thanks & Regards
Sumit Majumdar,
askIITians Faculty
Ph.D,IIT Delhi

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