Answer:
Densidad de la placa = 20 g/cm³.
La placa no es de oro.
Explanation:
Para encontrar la densidad de la placa rectangular primero debemos hallar su volumen:
Ahora, encontremos al densidad de la placa:

Dado que la densidad del oro es 19.32 g/cm³ y que la densidad de la placa rectangular calculada es 20 g/cm³, podemos decir que dicha placa no es de oro.
Espero que te sea de utilidad!
Answer:
The value is 
Explanation:
From the question we are told that
The mass of matter converted to energy on first test is 
The mass of matter converted to energy on second test 
Generally the amount of energy that was released by the explosion is mathematically represented as

=> ![E = 1.5 *10^{-3} * [ 3.0 *10^{8}]^2](https://tex.z-dn.net/?f=E%20%3D%20%201.5%20%2A10%5E%7B-3%7D%20%20%2A%20%5B%203.0%20%2A10%5E%7B8%7D%5D%5E2)
=> 
NB: The diagram of the pulley system is not shown but the information provided is sufficient to answer the question
Answer:
Power = 2702.56 W
Explanation:
Let the power consumed be P
Energy expended = E = mgh
height, h = 5 m
E = 80 * 9.8 * 5
E = 3920 J

To calculate the time, t
From F = ma
F = 900 N
900 = 80 a
a = 900/80
a = 11.25 m/s²
From the equation of motion, 
The drill head starts from rest, u = 0 m/s

Power, P = E/t
P = 3920/0.0.943
P = 4157.79 W
But Efficiency, E = 0.65
P = 0.65 * 4157.79
Power = 2702.56 W
Solution :
Given weight of Kathy = 82 kg
Her speed before striking the water,
= 5.50 m/s
Her speed after entering the water,
= 1.1 m/s
Time = 1.65 s
Using equation of impulse,

Here, F = the force ,
dT = time interval over which the force is applied for
= 1.65 s
dP = change in momentum
dP = m x dV
![$= m \times [V_f - V_o] $](https://tex.z-dn.net/?f=%24%3D%20m%20%5Ctimes%20%5BV_f%20-%20V_o%5D%20%24)
= 82 x (1.1 - 5.5)
= -360 kg
∴ the net force acting will be


= 218 N
Answer:
The right solution is "24.39 per sec".
Explanation:
According to the question,
⇒ 

The time will be:
⇒ 



hence,
⇒ 
