Answer:
420000N
Explanation:
Given parameters:
Mass of the train = 5.6 x 10⁵kg
Acceleration = 0.75m/s²
Unknown:
Resultant force = ?
Solution:
According to newton's second law, force is the product of mass and acceleration;
Force = mass x acceleration
Resultant force that acts on the train is given below;
Force = 5.6 x 10⁵kg x 0.75m/s² = 420000N
E. all of the above
An umbrella tends to move upward on a windy day because _<span>A. buoyancy increases with increasing wind speed </span>
<span>B. air gets trapped under the umbrella and pushes it up </span>
<span>C. the wind pushes it up </span>
<span>D. a low-pressure area is created on top of the umbrella </span>
Answer:
a) variation of the energy is equal to the work of the friction force
b) W = Em_{f} -Em₀
, c) he conservation of mechanical energy
Explanation:
a) In an analysis of this problem we can use the energy law, where at the moment the mechanical energy is started it is totally potential, and at the lowest point it is totally kinetic, we can suppose two possibilities, that the friction is zero and therefore by equalizing the energy we set the velocity at the lowest point.
Another case is if the friction is different from zero and in this case the variation of the energy is equal to the work of the friction force, in value it will be lower than in the calculations.
b) the calluses that he would use are to hinder the worker's friction force and energy
W = Em_{f} -Em₀
N d = ½ m v² - m g (y₂-y₁)
y₂-y₁ = 35 -10 = 25m
c) if there is no friction, the physical principle is the conservation of mechanical energy
If there is friction, the principle is that the non-conservative work is equal to the variation of the energy
Answer: Economic growth is the main channel. Globalization can affect poverty. when countries open up to trade, they tend to grow faster and living standards do tend to increase.
Explanation: I hope this helps :)
