See the attached picture:

- The angle between the two vectors is 90° .

- The dot product of two vectors .
- The cross product of two vectors .

⚡ Let
and
are the two vectors .
✍️ We have know that,

Where,



[1] The dot product of two vectors is “ <u>0</u> ” .
✍️ We have know that,

Where,



[2] The cross product of two vectors is “ <u>ab</u> ” .
Answer:
Physical science, Earth science, and life science.
Answer:
a) 3.43 m/s
Explanation:
Due to the law of conservation of momentum, the total momentum of the bullet - rifle system must be conserved.
The total momentum before the bullet is shot is zero, because they are both at rest, so:

Instead the total momentum of the system after the shot is:

where:
m = 0.006 kg is the mass of the bullet
M = 1.4 kg is the mass of the rifle
v = 800 m/s is the velocity of the bullet
V is the recoil velocity of the rifle
The total momentum is conserved, therefore we can write:

Which means:

Solving for V, we can find the recoil velocity of the rifle:

where the negative sign indicates that the velocity is opposite to direction of the bullet: so the recoil speed is
a) 3.43 m/s