Answer:
The applied force is greater than the frictional force.
Explanation:
the chair moves at <u>a constant speed</u><u> </u><u>therefore</u><u>,</u><u> </u><u>the</u><u> </u><u>answer</u><u> </u><u>is</u><u> </u><u>not</u><u> </u><u>A</u><u> </u><u>or</u><u> </u><u>C</u><u>.</u>
if there is no friction then the chair <u>would accelerate and it would not be at a constant speed</u><u>.</u>
hence, the only possible answer is B.
Answer:
v = 31.3 m / s
Explanation:
The law of the conservation of stable energy that if there are no frictional forces mechanical energy is conserved throughout the point.
Let's look for mechanical energy at two points, the highest where the body is at rest and the lowest where at the bottom of the plane
Highest point
Em₀ = U = m g y
Lowest point
= K = ½ m v²
As there is no friction, mechanical energy is conserved
Em₀ =
m g y = ½ m v²
v = √ 2 g y
Where we can use trigonometry to find and
sin 30 = y / L
y = L sin 30
Let's replace
v = RA (2 g L sin 30)
Let's calculate
v = RA (2 9.8 100.0 sin30)
v = 31.3 m / s
Answer:
a) correct answer is C
, b) 14º from the west to the north, c) v_{1g} = 300.79 km / h
Explanation:
This is a relative speed exercise using the addition of speeds.
1) when it is not specified regarding what is being measured, the medicine is carried out with respect to the Z Earth, therefore the correct answer is C
2 and 3) In this case we must compose the speed using the Pythagorean Theorem.
² =
² +
²
where v_{1a} is the speed of the airplane with respect to the air, v_{1g} airplane speed with respect to the Earth, v_{ag} air speed with respect to the Earth
in this case let's clear the speed of the airplane with respect to the Earth
v_{1g} = √(v_{1a}² - v_{ag}²)
v_{1g} = √ (310² - 75²)
v_{1g} = 300.79 km / h
we find the direction of the airplane using trigonometry
sin θ = v_{ag} / v_{1a}
θ = sin⁻¹ (v_{ag} /v_{1a})
θ = sin⁻¹ (75/310)
θ= 14º
the pilot must direct the aircraft at an angle of 14º from the west to the north
Electrostatic forces are non-contact forces; they pull or push on objects without touching them