<u>Answer:</u> The ball is travelling with a speed of 5.5 m/s after hitting the <u>bottle.</u>
<u>Explanation:</u>
To calculate the speed of ball after the collision, we use the equation of law of conservation of momentum, which is given by:

where,
are the mass, initial velocity and final velocity of ball.
are the mass, initial velocity and final velocity of bottle.
We are given:

Putting values in above equation, we get:

Hence, the ball is travelling with a speed of 5.5 m/s after hitting the bottle.
Answer:

Explanation:
given,
F = 14.1 i + 0 j + 5.1 k
displacement = 6 m
Assuming block is moving in x- direction
we know,
dW = F dx


![W = F[x]_0^6](https://tex.z-dn.net/?f=W%20%3D%20F%5Bx%5D_0%5E6)


hence, work done by the force is equal to 
Answer:
The girl will move with constant velocity
Explanation:
If after a certain time t_0 the velocity of the girl is v_0 =gt_0 and the upward force on the girl due to rope is mg ,where g is gravitational acceleration. Then the girl will move down with the constant velocity v_0 .
The girl will move with constant velocity,as explained above.
Answer:
0.2m
The solution is in the picture
Answer:

Explanation:
Two identical sticky masses m are moving in the xy-plane, with their momenta at an angle of φ with one another. They are each moving at the same speed v when they collide at the origin of the coordinates and stick together. After the collision, the masses move at an angle −θ2 with respect to the +x axis at speed v2 .1. What was the angle φ?
from the principle of momentum
In a system of colliding bodies,we know that the total momentum before collision will equal to the total momentum after collision.
Take note that momentum is the product of mass and velocity
momentum before collision=momentum after collision
mass, m
u=initial velocity of the identical masses
v2=the common velocity after the collision
Note that the collision is inelastic , since they both moved with the same velocity
umcosφ+umcosφ=(m+m)v2cos−θ2
2mucosφ=2mv2cos−θ2
