Do you have any other information? Like the velocity of the wave?
Answer:
the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°
Explanation:
Given the data in the question and as illustrated in the diagram below.
speed of the ship v = 0.90c
base of the ladder from the wall x₀ = 3.0 m
top of the later above the floor y = 4.0 m
we determine angle θ.
from the diagram,
tanθ = y/x₀
tanθ = y / x₀√( 1 - v²/c² )
we substitute
tanθ = 4.0 / 3.0√( 1 - ((0.9c)²/c²) )
tanθ = 4.0 / 3.0√( 1 - ((0.9²)c²/c²) )
tanθ = 4.0 / 3.0√( 1 - (0.9²) )
tanθ = 4.0 / 3.0√( 1 - 0.81 )
tanθ = 4.0 / 3.0√0.19
tanθ = 4.0 / 1.30766968
tanθ = 3.058876
θ = tan⁻¹( 3.058876 )
θ = 71.8965 ≈ 71.9°
Therefore, the angle the ladder makes with the floor as seen by an observer on Earth is 71.9°
Answer:
d) Gravity, a normal force, and kinetic friction
Explanation:
- When the bobsledder pushes her sled across horizontal snow to get it going, after she jumps into the sled there acts a force of gravity on the total mass of the sled including the bobsledder.
- The sled moves horizontally and not vertically this means that there is a normal force acting in the vertically upward direction opposite to the gravity.
- While the sled moves on the horizontal surface and comes to the rest there acts a kinetic frictional force on the body in the direction opposite to the direction of motion.
Answer:
Explanation:
Because the total energy available to the ball doesn't change whatsoever during its entire trip from the window to the ground,
TE = KE + PE which says that the total energy available to a system is equal to the kinetic energy of the system plus the potential energy, and that this value will not ever change (because energy cannot be created or destroyed. Sound familiar?) If the ball is being held still before it is dropped from some height off the ground, it is here that the total energy can be determined, and that total energy at this point is all potential, since the ball is not moving while someone is holding it and getting ready to drop it. The SECOND it starts to fall, the potential energy begins to be converted to kinetic. As the potential energy is losing value, the kinetic is gaining it at the same rate (again, energy doesn't just disappear; it has to go somewhere. Here, it goes from potential to kinetic a little at a time). When the ball finally hits the ground, or an INSTANT BEFORE it hits the ground, the potential energy is 0 because the height of something on the ground has a height of 0. At this instant, right before the ball hits the ground, is where the KE is the greatest. All the energy at that point has been converted from potential to kinetic.
Long story short, choice B is the one you want.
Answer: kooi kooi
how r u and thanks for the free points :)
