Answer: F = ma,
Explanation:
the most famous equation in physics, establishing an equivalence between energy and mass. But is this the most important equation in physics? Knowledgeable scientists will tell you no. The most important equation in physics is F = ma, also known as Newton's second law of mechanics.
The correct answer for the question that is being presented above is this one: "B.pushing against a car without moving it." According to the scientific definition, pushing against a car without moving it is not an example of work. Lifting a book off a desk and <span>pulling socks out of the drye are samples of work.</span>
Answer:
183333 Pa
Explanation:
The weight of the football player is : 550 N ,thus the force the player exerts on the floor is 550 N
The area of blades in contact with the floor is = 30cm² = 0.003 m²
Pressure = Force / Area
Pressure = 550 / 0.003
Pressure = 183333 Pa
Answer:
r = 1.61 x 10^{11} m
Explanation:
energy radiated (H) = 2.7 x 10^31 W
surface temperature (T) = 11,000 k
assuming ε = 1 and taking σ = 5.67 x 10^{-8} W/m^{2}.K^{4}
we can find the radius of the star from the equation below
H = A x ε x σ x T^{4}
where area (A) = 4 x π x r^{2} (assuming it is a sphere)
therefore the equation becomes
H = 4 x π x r^{2} x ε x σ x T^{4}
2.7 x 10^31 = 4 x π x r^{2} x 1 x 5.67 x 10^{-8} x (11,000)^{4}
r = 
r = 1.61 x 10^{11} m
Answer:
The rate of heat removed from inside the refrigerator is 300 watts.
Explanation:
By the First Law of Thermodynamics and the definition of a Refrigeration Cycle, we have the following formula to determine the rate of heat removed from inside the refrigerator (
), in watts:
(1)
Where:
- Rate of heat released to the room, in watts.
- Rate of electric energy needed by the refrigerator, in watts.
If we know that 
and 
, then the rate of heat removed from inside the refrigerator is:
The rate of heat removed from inside the refrigerator is 300 watts.
