Answer:
F=m x a
(F is force ,M is mass and A is acceleration)
in thisncase the Mass is given but we need to find ou the acceleration
Formula for acceleration-
a=(v - u)/t
(v is final velocity , u is initiatal velocity and t is time)
a = (0 - 80)/4
a= -80/4
a= -20
By substituting the values-
F= m x a
F= 1500 x -20
F=-30000N
Thus the force acted is -30000N
hope this helps
Answer:
The Sun and planets are shown to the same scale. The small terrestrial planets and tiny Pluto are in the box---the Earth is the blue dot near the center of the box (montage created by Nick Strobel using NASA images).
Size
The Sun is by far the biggest thing in the solar system. From its angular size of about 0.5° and its distance of almost 150 million kilometers, its diameter is determined to be 1,392,000 kilometers. This is equal to 109 Earth diameters and almost 10 times the size of the largest planet, Jupiter. All of the planets orbit the Sun because of its enormous gravity. It has about 333,000 times the Earth's mass and is over 1,000 times as massive as Jupiter. It has so much mass that it is able to produce its own light. This feature is what distinguishes stars from planets.
Composition
What is the Sun made of? Spectroscopy shows that hydrogen makes up about 94% of the solar material, helium makes up about 6% of the Sun, and all the other elements make up just 0.13% (with oxygen, carbon, and nitrogen the three most abundant ``metals''---they make up 0.11%). In astronomy, any atom heavier than helium is called a ``metal'' atom. The Sun also has traces of neon, sodium, magnesium, aluminum, silicon, phosphorus, sulfur, potassium, and iron. The percentages quoted here are by the relative number of atoms. If you use the percentage by mass, you find that hydrogen makes up 78.5% of the Sun's mass, helium 19.7%, oxygen 0.86%, carbon 0.4%, iron 0.14%, and the other elements are 0.54%.
Explanation:
Approximately 0.4373 seconds
Speed of sound at 20 degree C is roughly 343 meters/second
Speed of light = 3x10^8 or 300,000,000 meters/second
at 150.0 feet away you set it up as:
150.0/343 - 150/3x10^8
150.0/343 = 0.43731778
150/3x10^8 = 5x10^-7 or 0.0000005
Subtract 0.43731778 - 0.0000005
Answer is 0.43731728
Rounding would be approx. 0.4373
Answer:
0.972222........
Explanation:
1. Convert km/h to m/h by multiplying by 1000
2. Divide by 60 so that you have 58.3333... meters per minute
3. Divide by 60 again so now you have 0.972222... m/s
To solve this problem we must consider the expressions of Stefan Boltzmann's law for which the rate of change of the radiation of energy H from a surface must be

Where
A = Surface area
e = Emissivity that characterizes the emitting properties of the surface
= Universal constant called the Stefan-Boltzmann constant 
T = Absolute temperature
The total heat loss would be then





Therefore the net rate of heat loss from the body by radiation is 155.29J