Answer:
V = 10.88 m/s
Explanation:
V_i =initial velocity = 0m/s
a= acceleration= gsinθ-
cosθ
putting values we get
a= 9.8sin25-0.2cos25= 2.4 m/s^2
v_f= final velocity and d= displacement along the inclined plane = 10.4 m
using the equation


v_f= 7.04 m/s
let the speed just before she lands be "V"
using conservation of energy
KE + PE at the edge of cliff = KE at bottom of cliff
(0.5) m V_f^2 + mgh = (0.5) m V^2
V^2 = V_f^2 + 2gh
V^2 = 7.04^2 + 2 x 9.8 x 3.5
V = 10.88 m/s
Newton's second law states that the resultant of the forces applied to an object is equal to the product between the object's mass and its acceleration:

where in our problem, m is the mass the (child+cart) and a is the acceleration of the system.
We are only concerned about what it happens on the horizontal axis, so there are two forces acting on the cart+child system: the force F of the man pushing it, and the frictional force

acting in the opposite direction. So Newton's second law can be rewritten as

or

since the frictional force is 15 N and we want to achieve an acceleration of

, we can substitute these values to find what is the force the man needs:
Answer:
Blank One: I'm not certain but I'd assume it's either sound or energy.
Blank Two: Louder
Explanation:
volume is controlled by how much energy is put in an area per a unit of time, so the more energy in one area for a unit of time, the louder the sound will come out.
Sorry I couldn't give the best explanation!
Answer:
Speed is the time rate at which an object is moving along a path, while velocity is the rate and direction of an object's movement.
Answer:
(B) False
Explanation:
The visible light and the x-rays are part of the electromagnetic spectrum, all in the spectrum travel in the vacuum at the same speed, at the speed of light (c = 299,792,458 m/s ). If the visible light ant the x-rays are traveling inside a medium, their velocity will change due to the properties of the medium but in the vacuum, their speed is the same.