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Answer:
The direction of the contact forces acting on a body is not necessarily perpendicular to the contact surface. The resolution of contact forces in two components i.e. perpendicular to contact surface and along surface. Perpendicular component is normal force and parallel component is friction.
Explanation:
Answer:
The marble was moving in a projectile and the speed of the engine was 2.716 m/s
Explanation:
The vertical component of the marble's flight path relative to the train
is given by the equation y(t) = v*t - (4.9)*t^2,
where, v is the initial upward velocity of the marble relative to the train.
So with y(1) = v - 4.9 = 0 we have
v = 4.9 m/s.
The marble will reach maximum height after 0.5 seconds, at which the
height will be y(0.5) = (4.9)*(0.5) - (4.9)*(0.5)^2 = (4.9)*(0.25) = 1.225 m.
Now, the marble has a vertical velocity component of 4.9 m/s and a horizontal velocity component
of V m/s such that tan(61) = 4.9 / V
V = 4.9 / tan(61) = 2.716 m/s
This horizontal velocity component of the marble is the same as the
speed of the train i.e. 2.716 m/s.
Answer: Gamma rays, x-rays, ultraviolet rays, visible light, and infrared rays.
Answer:
to overcome the out of friction we must increase the angle of the plane
Explanation:
To answer this exercise, let's propose the solution of the problem, write Newton's second law. We define a coordinate system where the x axis is parallel to the plane and the other axis is perpendicular to the plane.
X axis
fr - Wₓ = m a (1)
Y axis
N-
= 0
N = W_{y}
let's use trigonometry to find the components of the weight
sin θ = Wₓ / W
cos θ = W_{y} / W
Wₓ = W sin θ
W_{y} = W cos θ
the friction force has the formula
fr = μ N
fr = μ Wy
fr = μ mg cos θ
from equation 1
at the point where the force equals the maximum friction force
in this case the block is still still so a = 0
F = fr
F = (μ mg) cos θ
We can see that the quantities in parentheses with constants, so as the angle increases, the applied force must be less.
This is the force that balances the friction force, any force slightly greater than F initiates the movement.
Consequently, to overcome the out of friction we must increase the angle of the plane
the correct answer is to increase the angle of the plane