The amount of heat needed to melt the block of lead is 
Explanation:
The amount of heat needed to melt a solid substance already at its melting point is given by the equation

where
m is the mass of the substance
is the specific latent heat of fusion
In this problem, we have a block of lead already at its melting point,
. Its mass is
m = 200 g = 0.2 kg
and its specific latent heat of fusion is

Therefore, the amount of heat needed for the block to completely melt is

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Answer:
Equation 2
Explanation:
Initial velocity ( Vo ) = 20 m/s
Acceleration ( a ) = 1.1 m/s^2
Distance ( d ) = 55 m
Final velocity ( Vi ) can be found using equation 2
AC reverses the current in periods, and the current flows in 2 directions.
DC only flows in one direction and is constant.
AC is typically used to transfer power over long distances from a generator to your home, stepping it up after it's generated to send it over the distance, then stepping it back down so that it is usable in your home.
DC is used typically inside of devices, as it sends a certain amount of electricity through the wires.
Nicolas Tesla, was ripped off by Edison to replace his DC stations with AC instead. ^^
Acceleration<span> is a vector quantity that is defined as the rate at which an object changes its velocity. An object is </span>accelerating<span> if it is changing its velocity. It can be calculated by the expression:
a = v2 - v1 / t
From the given in the problem, we can solve for v2, the final velocity:
3 = v2 - 0 / 300
v2 = 900 m/s</span>
Respuesta:
24m
Explicación:
Según la ecuación de movimiento
v = u + en
Dado
Velocidad final v = 12 m / s
velocidad inicial u = 0 m / s
tiempo t = 4s
Sustituir
12 = 0 + 4a
a = 12/4
a = 3 m / s²
Lo siguiente es obtener la distancia;
S = ut + 1 / 2at²
S = 0 (4) + 1/2 (3) (4) ²
S = 3 * 16/2
S = 48/2
S = 24 m
Por lo tanto, la distancia requerida es de 24 m.