The man is holding the suitcase at the same height above the surface of earth. So the gravitation potential energy remains the same.
<span>work done is force * displacement = weight * 0 = 0</span>
The maximum force of friction:
F = μ* N, where μ is the friction coefficient and N id the force of the doghouse normal to the surface.
N for a flat surface would be: N = m*g, where m is the mass and g is the gravitational acceleration = 9,81 m/s².
Combined:
F = μ * g * m
Answer:
C. Influenced by the Sun's electromagnetic field
Explanation:
"Sunspots occur in pairs because each is one side of a loop of the Sun's magnetic field that reaches the Sun's surface. Solar prominences are the plasma loops that connect two sunspots."
<span>The earth has hotter summers and cooler winters because the axis of the earth is tilted. In July, the earth is tilted on its axis and is the furthest away from the sun while in January it is tilted so that it is closest to the sun at that time of year. That said, during the summer months, due to the way the earth is tilted, the sun's rays hit the earth at a much more direct line meaning they are more powerful. THis, in turn, makes the summer much warmer than the winter.</span>
Answer:
x = A cos wt
Explanation:
To determine the position we are going to solve Newton's second law
F = m a
Spring complies with Hooke's law
F = -k x
And the acceleration of defined by
a = d²x / dt²
We substitute
- k x = m d²x / dt²
dx² / dt² + k/m x = 0
Let's call
w² = k / m
The solution to this type of differential equation is
x = A cos (wt + Ф)
Where A is the initial block displacement and the phase angle fi is determined by or some other initial condition.
In this case the body is released so that at the initial speed it is zero
From which we derive this expression
v = dx / dt = a w sin ( wt + Ф)
As the System is released for t = 0 the speed is v = 0
v = sin Ф = 0
Therefore Ф = 0
And the equation of motion is
x = A cos wt
