Answer:
ms⁻¹
Explanation:
Consider the motion of the bullet-block combination after collision
= mass of the bullet = 0.0382 kg
= mass of wooden block = 3.78 kg
= velocity of the bullet-block combination after collision
= spring constant of the spring = 833 N m⁻¹
= Amplitude of oscillation = 0.190 m
Using conservation of energy
Kinetic energy of bullet-block combination after collision = Spring potential energy gained due to compression of spring


ms⁻¹
= initial velocity of the bullet before striking the block
Using conservation of momentum for the collision between bullet and block


ms⁻¹
<em>Answer:</em>
<em>r=x+y</em>
<em>sorry if its not correct you can delete if you want.</em>
Answer:
460.52 s
Explanation:
Since the instantaneous rate of change of the voltage is proportional to the voltage in the condenser, we have that
dV/dt ∝ V
dV/dt = kV
separating the variables, we have
dV/V = kdt
integrating both sides, we have
∫dV/V = ∫kdt
㏑(V/V₀) = kt
V/V₀ = 
Since the instantaneous rate of change of the voltage is -0.01 of the voltage dV/dt = -0.01V
Since dV/dt = kV
-0.01V = kV
k = -0.01
So, V/V₀ = 
V = V₀
Given that the voltage decreases by 90 %, we have that the remaining voltage (100 % - 90%)V₀ = 10%V₀ = 0.1V₀
So, V = 0.1V₀
Thus
V = V₀
0.1V₀ = V₀
0.1V₀/V₀ = 
0.1 = 
to find the time, t it takes the voltage to decrease by 90%, we taking natural logarithm of both sides, we have
㏑(0.01) = -0.01t
So, t = ㏑(0.01)/-0.01
t = -4.6052/-0.01
t = 460.52 s