Answer:
t = 180 / 1.4 = 129 sec (time to swim horizontally across river)
S = 129 sec * V where V is speed of current and S is the distance he will be carried downstream
The problem does not specify V the speed of the river
<h3><u>Answer and explanation;</u></h3>
Reflection;
- Bounces back from an opaque material
- Bounces back from the boundary of two mediums
- Seen in mirrors
Refraction;
- Passes through a prism
- Moves from one medium to another
- Seen in lenses
Reflection refers to the bouncing of waves such as light waves. It involves a change in direction of waves when they bounce off a barrier.
Refraction is the bending of waves when they move from one medium to another. It involves a change in the direction of waves as they pass from one medium to another.
The value of the coefficient of kinetic friction between the wagon and inclined surface is 0.78.
<h3>
Coefficient of the kinetic friction</h3>
The value of coefficient of kinetic friction is calculated as follows;
F - Ff = ma
F - μmgcosθ = ma
where;
- F is applied force
- μ is coefficient of kinetic friction
- m is mass of the wagon
- a is acceleration of the wagon
182 - μ(20 x 9.8 x cos30) = 20(2.5)
182 - 169.74μ = 50
182 - 50 = 169.74μ
132 = 169.74μ
μ = 132/169.74
μ = 0.78
Thus, the value of the coefficient of kinetic friction between the wagon and inclined surface is 0.78.
Learn more about coefficient of friction here: brainly.com/question/20241845
Answer:
Norway, Sweden, Finland and Iceland
Explanation:
Sea ice is a frozen seawater that floats on the ocean surface. It is formed between the Antarctic and Arctic hemisphere. It disappears in summer but not completely. The countries that experienced sea ice in 1986 were eight (8) in number but the countries bordered by open water were in September 2017 were Norway, Iceland, Finland and Russia.