Answer:
2.26 s
Explanation:
The following data were obtained from the question:
Height (h) = 25 m
Acceleration due to gravity (g) = 9.8 m/s²
Time (t) =..?
The time taken for the egg to hit the floor can be obtained as illustrated below:
h = ½gt²
25 = ½ × 9.8 × t²
25 = 4.9 × t²
Divide both side by 4.9
t² = 25 / 4.9
Take the square root of both side
t = √(25 / 4.9)
t = 2.26 s
Thus, it will take 2.26 s for the egg to hit the floor.
Due that the velocity is constant that means that friction force is equal to the force exert by you, otherwise the refrigerator will accelerate or decelerate and in both cases velocity will not be constant.
So then the friction force between refrigerator and floor is 150 Newtons.
Answer:
Q = 1057.5 [cal]
Explanation:
In order to solve this problem, we must use the following equation of thermal energy.

where:
Q = heat energy [cal]
Cp = specific heat = 0.47 [cal/g*°C]
T_final = final temperature = 32 [°C]
T_initial = initial temperature = 27 [°C]
m = mass of the substance = 450 [g]
Now replacing:
![Q=450*0.47*(32-27)\\Q=1057.5[cal]](https://tex.z-dn.net/?f=Q%3D450%2A0.47%2A%2832-27%29%5C%5CQ%3D1057.5%5Bcal%5D)
Atomic number is equal to the number of protons and electrons
Atomic mass - protons = neutrons
protons + neutrons = atomic mass
I hope this helps