The solution for this problem:
Given:
f1 = 0.89 Hz
f2 = 0.63 Hz
Δm = m2 - m1 = 0.603 kg
The frequency of mass-spring oscillation is:
f = (1/2π)√(k/m)
k = m(2πf)²
Then we know that k is constant for both trials, we have:
k = k
m1(2πf1)² = m2(2πf2)²
m1 = m2(f2/f1)²
m1 = (m1+Δm)(f2/f1)²
m1 = Δm/((f1/f2)²-1)
m 1 = 0.603/
(0.89/0.63)^2 – 1
= 0.609 kg or 0.61kg or 610 g
Answer: 81.619 kJ
Explanation:
Given
Mass of roller coaster is 
It reaches the steepest hill with speed of 
Hill to bottom is 51 m long with inclination of 
Height of the hill is 
Conserving energy to get kinetic energy at bottom
Energy at top=Energy at bottom

Answer D
In alkali earth metals reacrivity increases from top to bottom (opposite of b)
This is because as you go down, the electron shells increase by 1 shell. The farther away a shell is from the nucleus, the higher its tendency to react.
D is true because the more reactive an alkali metal is, the more vigorous the reaction will be with water.
Answer:
B) The lightbulb uses 4,104,000 J more than the stereo.
Answer:
Los 0.0416km
esto se debe a que transponemos la fórmula acelerada y obtenemos Distancia = velocidad × tiempo
también recuerda transponer los segundos a horas viendo que la velocidad es por hora
También tenga en cuenta que no hablo español, así que esto fue extremadamente difícil
culto