Answer:
P = 1333.33 N
Explanation:
The pressure exerted by the boy on the floor can be calculated by the following equation:

where,
P = Pressure exerted by the boy = ?
F = Force Applied = Weight of Boy = 40 kg = 40 N (since 1 kg = 1N)
A = Area of application of force = 2(Area of one show) = 2(6 cm x 25 cm)
A = 2(0.06 m x 0.25 m) = 0.03 m²
Therefore,

<u>P = 1333.33 N</u>
Voltage of each component is same.
Answer:
4.5 m/s
Explanation:
The rock must barely clear the shelf below, this means that the horizontal distance covered must be

while the vertical distance covered must be

The rock is thrown horizontally with velocity
, so we can rewrite the horizontal distance as

where t is the time of flight. Re-arranging the equation,
(1)
The vertical distance covered instead is

where we omit the term
since the initial vertical velocity is zero. From this equation,
(2)
Equating (1) and (2), we can solve the equation to find
:

Answer:
the high temperature needed to operate this refrigerator is C) 137.4° C
Explanation:
Hello!
The carnot refrigeration cycle is one in which a machine absorbs heat from an enclosure and expels it to the surroundings, the equation that defines the COP performance coefficient for this cycle is:

COP=performance coefficient =2.1
T1= Low temperature
T2=high temperature
Now use algebra to find the high temperature

If we replace the values:
note = remember that the temperature must be in absolute units, for which we must add 273.15 to the low temperature to find the temperature in Kelvin
T1 = 5 + 273.15 = 278.15K

In celsius
T2=410.60-273.15=137.4° C
the high temperature needed to operate this refrigerator is C) 137.4° C