Potential energy are phones possessing junwj em
Answer:
a. 0.8 mW/m² b. 1.6 mW/m² c. 6.4 mW/m²
Explanation:
Intensity,I = P/A were P = power and A = area = 4πr² were r = distance from electric guitar = 5.0 m.
a. When P = 0.25 W, I = 0.25 W/4π5² = 0.25 W/100π = 0.00079 W/m² ≅ 0.0008 W/m² = 0.8 mW/m²
b. When P = 0.50 W, I = 0.50 W/4π5² = 0.50 W/100π = 0.00156 W/m² ≅ 0.0016 W/m² = 1.6 mW/m²
c. When P = 2.0 W, I = 2.0 W/4π5² = 2.0 W/100π = 0.00636 W/m² ≅ 0.0064 W/m² = 6.4 mW/m²
Answer:
The height of the package when it was released was 1102.5 meters
Explanation:
A package is dropped from a hovering helicopter
Dropped means the initial velocity of the package is zero
The package takes 15 seconds to strike the ground
Ignore the air resistance
We need to know the height of the package when it was released
, where h is the height of the package
from the ground, u is the initial velocity, g is the acceleration of gravity
and t is the time
u = 0 , t = 15 seconds , g = 9.8 m/s²
h = 1102.5 meters
<em>The height of the package when it was released was 1102.5 meters</em>
That's a formula that shows the relationship between three quantities ...
weight, mass, and acceleration. If you know any two of them, then you
can use this formula to find the one you don't know.
Examples:
==> I have a rock with 2 kilograms of mass.
The gravitational acceleration on Earth is 9.8 m/s² .
How much does my rock weigh on Earth ?
Weight = (mass) x (grav acceleration)
= (2 kg) x (9.8 m/s²)
= 19.6 newtons
(about 4.41 pounds)
==> My brother weighs 770 newtons (about 173 pounds) on Earth.
What is his mass ?
Weight = (mass) x (grav acceleration)
770 newtons = (mass) x (9.8 m/s²)
Divide each side
by 9.8 m/s²: 770 newtons / 9.8 m/s² = mass
78.57 kilograms = mass
==> When I went to the Moon, I took along my 2-kilogram rock.
I weighed my rock on the Moon.
It weighs 3.25 newtons (about 0.73 pound) there.
What is the gravitational acceleration on the Moon ?
Weight = (mass) x (grav acceleration)
3.25 newtons = (2 kg) x (acceleration)
Divide each side
by 2 kilograms: (3.25 newtons)/(2 kg) = acceleration
1.63 m/s² = grav acceleration on the Moon
