To solve this problem it is necessary to apply the equations related to the Force of Friction and Energy.
By definition the friction force is defined as
Where,
Frictional Constant
N = Normal Force -> mg
At the same time we have the definition of the Energy, which can be
E = F*v
Where,
Force
v = Velocity.
Then replacing with our values we have that,
F = 0.5 *34
F = 17
The energy then would be,
E = f v
E = 17 * 0.30 = 5.1 W
Therefore the rate at which heat is generated is 5.1W
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