Question

Two vectors have magnitudes 3 and 5. If angle between them is 60$^{\circ}$, then the dot product of two vectors will be

• A. 7.5
• B. 6.5
• C. 8.4
• D. 7.9

Answer 1

Answer: (A)

7.5

Answer 2

Given A = 3. B = 5 and $\theta$ = 60$^{\circ}$
$A . B = 3 \times 5 \times cos \, 60^\circ$
$A . B = 15 \times \frac{1}{2} = 7.5$