Answer:
i) 24.5 m/s
ii) 30,656 m
iii) 89,344 m
Explanation:
Desde una altura de 120 m se deja caer un cuerpo. Calcule a 2.5 s i) la velocidad que toma; ii) cuánto ha disminuido; iii) cuánto queda por hacer
i) Los parámetros dados son;
Altura inicial, s = 120 m
El tiempo en caída libre = 2.5 s
De la ecuación de caída libre, tenemos;
v = u + gt
Dónde:
u = Velocidad inicial = 0 m / s
g = Aceleración debida a la gravedad = 9.81 m / s²
t = Tiempo de caída libre = 2.5 s
Por lo tanto;
v = 0 + 9.8 × 2.5 = 24.5 m / s
ii) El nivel que el cuerpo ha alcanzado en 2.5 segundos está dado por la relación
s = u · t + 1/2 · g · t²
= 0 × 2.5 + 1/2 × 9.81 × 2.5² = 30.656 m
iii) La altura restante = 120 - 30.656 = 89.344 m.
Answer:
The induced emf in the coil is 0.522 volts.
Explanation:
Given that,
Radius of the circular loop, r = 9.65 cm
It is placed with its plane perpendicular to a uniform 1.14 T magnetic field.
The radius of the loop starts to shrink at an instantaneous rate of 75.6 cm/s , 
Due to the shrinking of radius of the loop, an emf induced in it. It is given by :

So, the induced emf in the coil is 0.522 volts.
When atoms lose electrons they become positively charged ! When atoms gain electrons they become negatively charged !
Convert 10mm to metres = 0.01m
Wave speed = frequency *wavelength
= 4Hz*0.01m
= 0.04 m/s
Hope this helps