Answer:
the buoyant force F will be 0.84 N
Explanation:
Assuming that a person has the density of water , then its volume could be calculated through
V= m/ρ , where m= mass of the person , ρ= density of water
then
V= m/ρ = 70 kg/ 1000 kg/m³ = 0.07 m³
then the buoyant force will be equal to the mass of displaced air in the volume V.
if we assume that the density of air in the atmosphere is ρa=1.225 kg/m³ then the buoyant force F will be
F= ρa*V*g = 0.07 m³*1.225 kg/m³ *9.8 m/s² =0.84 N
Answer:
Approximately 3.03 seconds.
Explanation:
The distance traveled in the vertical direction is given by the kinematic equation:
Where <em>v</em>_<em>iy</em> and <em>a</em> are the initial velocity and acceleration of the object, respectively, in the vertical direction.
Because the rock is thrown horizontally, there is no horizontal velocity. Therefore:
The vertical acceleration is simply gravity <em>g. </em>This, this yields the general equation:
Substitute 45 m for <em>y</em> and solve for time <em>t:
</em>
Therefore, it will take approximately 3.03 seconds for the rock to fall 45 meters vertically.
The wave oscillates in a single plane. so the answer would be (c) i think
A. Air, desk, water. sound travels the slowest through air and the fastest through liquids. solids are somewhere in the middle.
Answer:
B.
Explanation:
Solar radiation that is not absorbed or reflected by the atmosphere (for example by clouds) reaches the surface of the Earth. The Earth absorbs most of the energy reaching its surface, a small fraction is reflected. In total approximately 70% of incoming radiation is absorbed by the atmosphere and the Earth’s surface while around 30% is reflected back to space and does not heat the surface. The Earth radiates energy at wavelengths much longer than the Sun because it is colder. Part of this longwave radiation is absorbed by greenhouse gases which then radiate energy into all directions, including downwards and thereby trapping heat in the atmosphere.
Hope this helps, sorry if it is incorrect. Have a great day/night!