Answer:
The magnitude of the acceleration of the elevator is 0.422 m/s²
Explanation:
Lets explain how to solve the problem
Due to Newton's Law ∑ Forces in direction of motion is equal to mass
multiplied by the acceleration
We have here two forces 460 N in direction of motion and the weight
of the person in opposite direction of motion
The weight of the person is his mass multiplied by the acceleration of
gravity
→ W = mg , where m is the mass and g is the acceleration of gravity
→ m = 45 kg and g = 9.8 m/s²
Substitute these values in the rule above
→ W = 45 × 9.8 = 441 N
The scale reads 460 N
→ F = 460 N , W = 441 N , m = 45 kg
→ F - W = ma
→ 460 - 441 = 45 a
→ 19 = 45 a
Divide both sides by 45
→ a = 0.422 m/s²
<em>The magnitude of the acceleration of the elevator is 0.422 m/s²</em>
Answer:
A) and B) are correct.
Explanation:
If the object is at rest, it means that no net force is exerted on it.
As the object experiences a downward gravitational force from Earth, in order to be at rest, it must experience an upward force with the same magnitude as the gravitational force on the object.
This force is supplied by the normal force, which can adopt any value in order to meet the condition imposed by Newton´s 2nd Law, and is always perpendicular to the surface on which the object is placed (in this case, the ground).
At a molecular level, this normal force is supplied by the bonded molecules of the ground that behave like small springs being compressed by the molecules of the object, exerting an upward restoring force upward on them.
So, the statements A) and B) are true.
Tuberculosis. Reason: I just took the test and got it right
Explanation:
It's displacement would be negative
displacement is a vector quantity.
'Backwards', we can assume, would be negative.
and forwards, positive. So going backwards would mean a negative displacement.
