Answer:

Explanation:
Given that
Mass of rifle = M
Initial velocity ,u= 0
Mass of bullet = m
velocity of bullet = v
Lets take final speed of the rifle is V
There is no any external force ,that is why linear momentum of the system will be conserve.
Initial linear momentum = Final linear momentum
M x 0 + m x 0 = M x V + m v
0 = M x V + m v

Negative sign indicates that ,the recoil velocity will be opposite to the direction of bullet velocity.
Answer:
T_finalmix = 59.5 [°C].
Explanation:
In order to solve this problem, a thermal balance must be performed, where the heat is transferred from water to methanol, at the end the temperature of the water and methanol must be equal once the thermal balance is achieved.

where:

mwater = mass of the water = 0.4 [kg]
Cp_water = specific heat of the water = 4180 [J/kg*°C]
T_waterinitial = initial temperature of the water = 85 [°C]
T_finalmix = final temperature of the mix [°C]

Now replacing:
![0.4*4180*(85-T_{final})=0.4*2450*(T_{final}-16)\\142120-1672*T_{final}=980*T_{final}-15680\\157800=2652*T_{final}\\T_{final}=59.5[C]](https://tex.z-dn.net/?f=0.4%2A4180%2A%2885-T_%7Bfinal%7D%29%3D0.4%2A2450%2A%28T_%7Bfinal%7D-16%29%5C%5C142120-1672%2AT_%7Bfinal%7D%3D980%2AT_%7Bfinal%7D-15680%5C%5C157800%3D2652%2AT_%7Bfinal%7D%5C%5CT_%7Bfinal%7D%3D59.5%5BC%5D)
In a reaction with a directing vendor of the sum forces towards some object or nothing
Answer:
The minimum speed of the box bottom of the incline so that it will reach the skier is 8.19 m/s.
Explanation:
It is given that,
Mass of the box, m = 2.2 kg
The box is inclined at an angle of 30 degrees
Vertical distance, d = 3.1 m
The coefficient of friction, 
Using the work energy theorem, the loss of kinetic energy is equal to the sum of gain in potential energy and the work done against friction.


W is the work done by the friction.







v = 8.19 m/s
So, the speed of the box is 8.19 m/s. Hence, this is the required solution.
The greater the mass of an object, the more inertia it has, so the object resists changes to its motion better.