Question

solve the Question fast plz​

Answer 1

v = u + at = 3i +4j + 10(0.3i +0.4j)

= 3i +4j +4i + 3j

= 7i +7j

so magnitude of final velocity is √(7²+7²)= 7√2

Since the third vector has a component which lies outside the plane of the remaining two, hence this extra component can not be cancelled by any other component during addition, so sum can never be zero.

Also, the sum lies outside the plane of  

A

+  

B

 (which is the same plane as  

A

 and  

B

) because of this extra component of  

C

 

Answer 2

Answer:

$11) \: see \: fig. \: in \: attachment$

$let \: an = x = nb$

$= > on = z$

$\frac{dz}{zt} = > v_{m}$

$\frac{dl}{dt} = 4$

$in \: triangle \: oan \: = >$

${l}^{2} = {n}^{2} + {z}^{2} ......(i)$

$diff. \: with \: respect \: to \: t$

$= > 2l \: \frac{dl}{dt} = 0t \: 2z \: \frac{dz}{dt}$

cancel 2 by 2

$\frac{dl}{dt} = u \: \: \: \: \frac{dz}{dt} = v_{m}$

$= > lu = z v_{m}$

$= > v_{m} = \frac{lu}{z} = \frac{u}{ \frac{z}{l} }$

$= > v_{m} = \frac{u}{ \cos \theta }$

so option b is correct in 11 Question

HOPE it's helps you ❤️