The answer would be c because a surface wave travels between two different materials, like air and water.
F = m · a
In order to accelerate 82 kg upward at the rate of 3.2 m/s², a NET upward force of (82kg · 3.2m/s²) = 262.4 Newtons is required.
But if the object is on or near the surface of the Earth, then there's a downward force of (82kg · 9.8m/s²) = 803.6 N already acting on it because of gravity.
So you need to apply (803.6N + 262.4N) = <em>1,066 Newtons UPward</em>, in order to cancel its own weight and accelerate it upward at that rate.
Answer:
D. When the box is placed in an elevator accelerating upward
Explanation:
Looking at the answer choices, we know that we want to find out how the normal force varies with the motion of the box. In all cases listed in the answer choices, there are two forces acting on the box: the normal force and the force of gravity. These two act in opposite directions: the normal force, N, in the upward direction and gravity, mg, in the downward direction. Taking the upward direction to be positive, we can express the net force on the box as N - mg.
From Newton's Second Law, this is also equal to ma, where a is the acceleration of the box (again with the upward direction being positive). For answer choices (A) and (B), the net acceleration of the box is zero, so N = mg. We can see how the acceleration of the elevator (and, hence, of the box) affects the normal force. The larger the acceleration (in the positive, i.e., upward, direction), the larger the normal force is to preserve the equality: N - mg = ma, N = ma+ mg. Answer choice (D), in which the elevator is accelerating upward, results in the greatest normal force, since in that case the magnitude of the normal force is greater than gravity by the amount ma.
Answer: The surface of the pad pushes the rocket up while gravity tries to pull it down. As the engines are ignited, the thrust from the rocket unbalances the forces, and the rocket travels upward. Later, when the rocket runs out of fuel, it slows down, stops at the highest point of its flight, then falls back to Earth.
Explanation:
To me, it's option 1
Newton third law states that Every action produces an equal and opposite reaction. Hence, given the fact that the engine is on, it should be producing a constant force every time so, the speed should be constant as the force propelling it is the same
