Answer:
vDP = 21.7454 m/s
θ = 200.3693°
Explanation:
Given
vDE = 7.5 m/s
vPE = 20.2 m/s
Required: vDP
Assume that
vDE to be in direction of - j
vPE to be in direction of i
According to relative motion concept the velocity vDP is given by
vDP = vDE - vPE (I)
Substitute in (I) to get that
vDP = - 7.5 j - 20.2 i
The magnitude of vDP is given by
vDP = √((- 7.5)²+(- 20.2)²) m/s = 21.7454 m/s
θ = Arctan (- 7.5/- 20.2) = 20.3693°
θ is in 3rd quadrant so add 180°
θ = 20.3693° + 180° = 200.3693°
Answer:
La posición en la que se encuentra el móvil en el instante t = 30 s es 172 m.
Explanation:
El movimiento rectilíneo uniforme (MRU) es el movimiento que describe un cuerpo o partícula a través de una línea recta a velocidad constante.
La distancia recorrida, x
, por un móvil que tiene un MRU con un velocidad v durante el intervalo de tiempo t es:
x= x0 + v*t
donde x0 es la posición inicial.
En este caso:
Reemplazando:
x= 22 m + 5 m/s* 30 s
Resolviendo:
x= 22 m + 150 m
x= 172 m
<u><em>La posición en la que se encuentra el móvil en el instante t = 30 s es 172 m.</em></u>
The horizontal force needed to start the calculator moving from rest is 1.5 N
What is Kinetic friction?
It is defined as a force that acts between moving surfaces.
The magnitude of the force will depend on the coefficient of kinetic friction between the two materials.
Here,
weight of calculator, N = 3 N
The coefficients of static frictions, µ (static) = 0.50
The coefficients of kinetic frictions, µ (kinetic) = 0.40
Now,
The horizontal force required = The static friction force
F = µ (static) * weight of calculator
F = 0.50 * 3.0
F = 1.5 N
Hence,
The horizontal force needed to start the calculator moving from rest is 1.5 N
Learn more about horizontal force here:
<u>brainly.com/question/21481680</u>
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