<span>The multiple reflection of a single sound wave is echo</span>
For #5 It's helpful to draw a free body diagram so you know which way the forces are acting on the block.
the weight mg is acting downwards, and you need to find the vertical and horizontal components of mg using sin and cosine. so do 15x9.8xsin40 which is the force. Assuming no friction, this is the only force acting on the block, as the forces on the vertical plane cancel out i.e the normal force and weight of the block.
after, just do F=ma And since you know F and m, solve for a.
<span>A series circuit has one path for electrons, but a parallel circuit has more than one path.</span>
Answer:

Explanation:
The root mean square velocity of the gas at an equilibrium temperature is given by the following formula:

where,
v = root mean square velocity of molecules:
R = Universal Gas Constant
T = Equilibrium Temperature
M = Molecular Mass of the Gas
Therefore,
For T = T₁ :

For T = T₂ :

Since both speeds are given to be equal. Therefore, comparing both equations, we get:
