D, Metamorphism
-Metamorphic rocks are any rocks that change into another rock when subjected to high heat and pressure.
When you squish the spring, you put some energy into it, and after the cord
burns and they go boing in opposite directions, that energy that you stored
in the spring is what gives the blocks their kinetic energy.
But linear momentum still has to be conserved. It was zero while they were
tied together and nothing was moving, so it has to be zero after they both
take off.
Momentum = (mass) x (velocity)
After the launch, the 5.5-kg moves to the right at 6.8 m/s,
so its momentum is
(5.5 x 6.8) = 37.4 kg-m/s to the right.
In order for the total momentum to be zero, the other block has to
carry the same amount of momentum in the opposite direction.
M x V = (6 x speed) = 37.4 kg-m/s to the left.
Divide each side by 6 : Speed = 37.4 / 6 =<em> 6.2333... m/s left</em>
(That number is (6 and 7/30) m/s .)
Impulse is the change of momentum before and after the collision:
I = mv₁ - mv₂ = m (v₁-v₂)
m mass
v velocity
Impuls also is defined as the average force during a short period of time:
I = F * t = m * a * t
F average force
t time difference
m mass
a average acceleration
Combined:
m(v₁- v₂) = m * a * t
a = (v₁- v₂) / t
= (4m/s - (-3m/s)) / 6s - 5s
= 7m/s / 1s
= 7 m/s²
Answer:
155.5 rev/min
Explanation:
First, we will calculate the initial moment of inertia I_o. We will consider the ice skater as a rod rotating around its axis. Then, we calculate the final moment of inertia I_f. In this occasion we consider the arms as a rod of length L that is horizontally positioned, L so that the length of an arm is L/2. We will call M_1 the mass that remains close to the rotation axis (90 percent) and M_2 the mass located at the arms (10 percent). Finally, we write the equation for the conservation of angular momentum and we solve for ω_f.
I_o=MR^2/2
=(45)(0.15)^2/2
=0.5 kgm^2
M_1=(0.9)(45)
=40.5 kg
M_2=(0.1)(45)
=4.5 kg
I_f=M_1*R^2/2+M_2*L^2/12
=1.1 kg m^2
I_f*ω_f=I_o*ω_o
ω_f = I_o*ω_o/ I_f
=155.5 rev/min
Rarefraction.
Crest- tallest spot on transverse wave.
Trough- shortest point on transverse wave.
Compression - spot on a compressional wave where the waves are closer together.
Rarefraction - spot on a compressional wave where the waves are farther apart.