D) waves are used to transmit the rail signal though the air. these waves are encoded at different frequencies for different stations
Answer:
v_f = 24.3 m / s
Explanation:
A) In this exercise there is no friction so energy is conserved.
Starting point. On the roof of the building
Em₀ = K + U = ½ m v₀² + m g y₀
Final point. On the floor
Em_f = K = ½ m v_f²
Emo = Em_g
½ m v₀² + m g y₀ = ½ m v_f²
v_f² = v₀² + 2 g y₀
let's calculate
v_f = √(10² + 2 9.8 25)
v_f = 24.3 m / s
Answer:
kinetic energy at first
Explanation:
kinetic turns to potential as it gains height
Answer:
354.72 m/s
Explanation:
= mass of lead bullet
= specific heat of lead = 128 J/(kg °C)
= Latent heat of fusion of lead = 24500 J/kg
= initial temperature = 27.4 °C
= final temperature = melting point of lead = 327.5 °C
= Speed of lead bullet
Using conservation of energy
Kinetic energy of bullet = Heat required for change of temperature + Heat of melting
