I don’t get how to answer the questions.
1 answer:
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Answer:
N = 648.55[N]
Explanation:
To solve this problem we must use Newton's second law which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
∑F = Forces applied [N]
m = mass = 73.2 [kg]
a = acceleration = 0.950 [m/s²]
Let's assume the direction of the upward forces as positive, just as if the movement of the box is upward the acceleration will be positive.
By performing a summation of forces on the vertical axis we obtain all the required forces and other magnitudes to be determined.
where:
g = gravity acceleration = 9.81 [m/s²]
N = normal force (or weight) measured by the scale = 83.4 [N]
Now replacing:
The acceleration has a negative sign, this means that the elevator is descending at that very moment.
Missing figure: find it in attachment.
Answer:
Force D
Explanation:
In order to answer the question, let's keep in mind that the force of gravity on an object on Earth is the attractive force exerted by the Earth on the object; its direction is always downward (towards the Earth's centre), and its magnitude is given by
F = mg
where m is the mass of the object and g is the acceleration of gravity.
It follows immediately that in the figure, the force of gravity is the only force acting downward: therefore, force D.
The other forces are called:
Force A: thrust (it is the forward force generated by the engines)
Force B: lift (it is the upward produced by the aerodynamics of the wings)
Force C: air resistance (it is the backward force due to the friction between the air and the surface of the plane)
