Answer:
microwave, visible light, and radio waves.
Explanation:
<h3>One reason we should know what the directions of the forces acting on an object is so we can know if we have to add or subtract. same = add together, opposite = subtract from each other. Also if we don't pay attention to the direction the Net force will be wont be accurate. There will be factors that will upset the calculation.So we must know the direction of the two forces because we have to know if we are adding or subtracting and if the answer is accurate. </h3>
<em>I hope this helps!.</em>
Answer:
(i) The maximum acceleration upward is 2.02 m/s².
(ii) The maximum acceleration downward is 1.39 m/s².
Explanation:
Let a be the maximum acceleration of the elevator.
The mass of the person at ground is 150 lb. We have to convert the mass into kg,
1 lb = 0.453592 kg
150 lb = 68 kg
170 lb = 77 kg
120 lb = 54 kg
(i) The person experience a force due to Earth's gravity in the downwards direction. The magnitude of this force is:
F₁ = mg = 68 x 9.8 = 666.4 N
The weight of the person decreases as the elevator is moving upwards. So, the force experienced by the person in this case due to gravity is:
F₂ = 54 x 9.8 = 529.2 N
Applying Newton's force equation;
(F₁ - F₂) = ma
(666.4 - 529.2) = 68 x a
a = 2.02 m/s²
(ii) The weight of the person increases as the elevator is moving downwards. So, the force experienced by the person in this case due to gravity is:
F₂ = 77 x 9.8 = 754.6 N
Applying Newton's force equation;
(F₁ - F₂) = ma
(666.4 - 754.6) = 68 x a
a = -1.30 m/s²
They have a uniform luminosity and are similar to the bulge in a spiral galaxy, but with no disk. The stars are old and there is no gas present. Ellipticals are usually found in the high density field, at the centre of clusters.
