What is the energy Q released when 131 53Idecays and 131 54Xe is formed? The atomic mass of 131 53I is 130.906118 u and the atom
1 answer:
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The question is missing its alternatives. Here is the complete question.
Consider two identical objects released from rest high above the surface of Earth. In Case 1, the object is released from a height above the surface of Earth equal to 1 Earth radius, and we measure its kinetic energy just before it hits the Earth to be K1. In Case 2, the obejct is released from a height above the surface of Earth equal to 2 Earth radii and its kinetic energy just before it hits is K2.
1. Compare the kinetic energy of the two objects just before they hit the surface of the earth.
a) K2 = 2K1; b) K2 = 4K; c) K2 = (4/3)K1; d) K2 = (3/2)K1;
Answer: C) K2 = (4/3)K1
Explanation: As it is related to the gravity of the Earth, the potencial energy is: U(r)= - + U₀
In this case, U₀=0, G is the universal gravitational constant, Me is the mass of Earth, m is the mass of the object and r is the distance between the center of the Earth and the object.
The potencial energy of an object of mass m on the surface of the Earth is:
Usurface = -
The potencial energy of the object in Case 1 is
U1 = -
For the Case 2:
U2 = -
The potencial change in Case 1:
ΔU1 = - G.Me.m.() = -
For Case 2:
ΔU2 = - G.Me.m() = -
Comparing ΔK1 and ΔK2 equals comparing ΔU1 and ΔU2:
Δ = (-2/3)(-1/2) = 4/3
So, comparing kinetic energies, K2 is 4/3 of K1.
Answer
given,
speed of sound = 344 m/s
speed of train = 30 m/s
frequency emitted by the train = 262 Hz
Doppler's effect
f_L is the frequency of listener
f_S is the frequency of the source of the sound
v is the speed of the sound
v_L is the speed of listener.
v_S is the speed of the source
a) Speed of the passenger in another train , v = 18 m/s
another train is moving in opposite direction and approaching
v_L is positive as the listener is moving forward.
v_S is negative at the source is moving toward the listener.
b) Speed of the passenger in another train , v = 18 m/s
another train is moving in opposite direction and receding
v_L is negative as the listener is moving away from source.
v_S is positive at the source is moving away the listener.