Answer:
ultra sounds have frequency higher than the upper audible limit of human hearing, for healthy, young adults.
Explanation:
Answer:
The magnitude of the net force is √2F.
Explanation:
Since the two particles have the same charge Q, they exert the same force on the test charge; both attractive or repulsive. So, the angle between the two forces is 90° in any case. Now, as we know the magnitude of these forces and that they form a 90° angle, we can use the Pythagorean Theorem to calculate the magnitude of the resultant net force:

Then, it means that the net force acting on the test charge has a magnitude of √2F.
Answer:
b. The normal force between the molecules of the paper is overcome by the contact force of the hands.
Explanation:
The paper molecules are held together by a weak bond. When the student holds the paper on both sides with the center of the paper in between, the student applies two equal forces in the opposite direction of the paper making the paper molecules weaken and separate.
Answer:
~~Now, you have left your question very open ended and didn't ask for any particular kind of answer so I'll do my best to get what you're looking for.~~
A physical change in a substance doesn't change what the substance is. It can possibly melt or freeze an object. I mean heat makes things expand while cooling makes them retract.... In chemical change where there is a chemical reaction, a new substance is formed and energy is either given off or absorbed.
Answer:
Speed =0.283m/ s
Direction = 47.86°
Explanation:
Since it is a two dimensional momentum question with pucks having the same mass, we derive the momentum in xy plane
MU1 =MU2cos38 + MV2cos y ...x plane
0 = MU2sin38 - MV2sin y .....y plane
Where M= mass of puck, U1 = initial velocity of puck 1=0.46, U2 = final velocity of puck 1 =0.34, V2 = final velocity of puck 2, y= angular direction of puck2
Substitute into equation above
.46 = .34cos38 + V2cos y ...equ1
.34sin38 = V2sin y...equ2
.19=V2cos Y...x
.21=V2sin Y ...y
From x
V2 =0.19/cost
Sub V2 into y
0.21 = 0.19(Sin y/cos y)
1.1052 = tan y
y = 47.86°
Sub Y in to x plane equ
.19 = V2 cos 47.86°
V2=0.283m/s