Momentum is conserved if and only if sum of all forces which are exserted on system equals zero. In our situation there are only internal forces, so by Newton's third law their vector sum is 0.
So 
.
Kinetic energy of system at first: 
. After: 
. The secret is that other energy is in work of deformation forces (they in turn heat a bullet and a block).
Answer is A)
Answer:
Check the explanation
Explanation:
The beat frequency is
df = f2 - f1
the wavelength is
lamda1 = (v/f1)
and lamda2 = (v/f2)
where v = 340 m/s,f1 = 25.0 kHz and f2 = 20.0 kHz
The solution you should use is Hooke's law: F=-kx
It should have the same signs because they repel due to the stretch of the spring.
a. Since there is a constant energy within the spring, then Hooke's law will determine the possible algebraic signs. The solution should be
<span>F = kx
270 N/m x 0.38 m = 102.6 N
</span>
b. Then use Coulomb's law; F=kq1q2/r^2 to find the charges produced in the force.
Answer:
1.85c
Explanation:
a photon moves at c, the electron is moving at 0.85c, and since they are moving in opposing directions, the relative speed would be 1.85c
