Answer:
t=20s
Explanation:
To solve this problem we must apply the first law of thermodynamics, which indicates that the energy that enters a system is the same that must come out, resulting in the following equation
For this problem we will assume that the water is in a liquid state, since it is a domestic refrigerator
q=m.cp.(T2-T1)
q=heat
m=mass of water =600g=0.6Kg
cp=
specific heat of water=4186J/kgK
T2=temperature in state 2=20°C
T1=temperature in state 1=0°C
solving:
q=(0.6)(4186)(20-0)=50232J
A refrigerator is a device that allows heat to be removed to an enclosure (Qin), by means of the input of an electrical energy (W) and the heat output (Qout), the coefficient of performance COP, allows to know the ratio between the heat removed ( Qin) and the added electrical power (W), the equation for the COP is

To solve this exercise we must know the value of the heat removed to the water (Qin)
solving for Qin
Qin=(COP)(Win)
Qin=(5)(500W)=2500W
finally we remember that the definition of power is the ratio of work over time
w=work
p=power=500w

Geothermal energy.
Electromagnetic energy originates at the sun (think UV rays; they are part of the electromagnetic spectrum). Electrical energy technically can be anywhere, as long as there are positive and negative charges. Mechanical energy is like a generator or an engine; there is always something working to get things done/made.
I hope this answer and these explanations helped!
Answer:
a) 
b) 
c) 
Explanation:
From the exercise we know the initial velocity of the projectile and its initial height

To find what time does it take to reach maximum height we need to find how high will it go
b) We can calculate its initial height using the following formula
Knowing that its velocity is zero at its maximum height



So, the projectile goes 1024 ft high
a) From the equation of height we calculate how long does it take to reach maximum point



Solving the quadratic equation



So, the projectile reach maximum point at t=2s
c) We can calculate the final velocity by using the following formula:


Since the projectile is going down the velocity at the instant it reaches the ground is:
