We know that a wave is a disturbance that transfers energy through matter or space There are two main types of waves: Mechanical and Electromagnetic. Water waves are mechanical. A mechanical wave is an oscillation of matter to transfers energy, but you always need a medium (substance such as: solid, liquid, gas, plasma) to transport it. The medium for water waves is, in fact, the water. For example, ripple in water is a surface wave. On the other hand, electromagnetic waves don't need a medium to transport, they can do it through the empty space. Then, this is the major characteristic that makes these two types of waves different.
D. Velocity because it describes a speed and direction
<span>Assuming that the momenta of the two pieces are equal: when they have equal velocities, then
the masses of the two pieces are also equal.
Since there is no force from outside of the system, the center of mass moves on with the same velocity as before the equation. So the two pieces must fly at the side side of the mass center, i.e., they must always be at 90° to the side of the mass center. Otherwise it would not be the mass center, respectively the pieces would not have equal velocities.
This is only possible, when the angle of their velocity with the initial direction is 60°.
Because, cos (60°) = 1/2 = v/(2v).</span>
Answer:
1. 20.54m/s
2. 1.52s
Explanation:
QUESTION 1:
The speed the stone impact the ground is the final speed/velocity, which can be calculated using the formula:
v² = u² + 2as
Where;
v = final velocity (m/s)
u = initial velocity (m/s)
a = acceleration due to gravity (m/s²)
s = distance (m)
From the provided information, u = 5.65m/s, v = ?, s = 19.9m, a = 9.8m/s²
v² = 5.65² + 2 (9.8 × 19.9)
v² = 31.9225 + 2 (195.02)
v² = 31.9225 + 390.04
v² = 421.9625
v = √421.9625
v = 20.5417
v = 20.54m/s
QUESTION 2:
Using v = u + at
Where v = final velocity (m/s) = 20.54m/s
t = time (s)
u = initial velocity (m/s) = 5.65m/s
a = acceleration due to gravity (m/s²)
v = u + at
20.54 = 5.65 + 9.8t
20.54 - 5.65 = 9.8t
14.89 = 9.8t
t = 14.89/9.8
t = 1.519
t = 1.52s
I'm guessing that this is a problem to find the weight of a 90kg mass on a planet where the acceleration of gravity is 4 m/s^2. (Much less gravity than Earth, a little more than Mars.)
Just do the multiplication, and you get
360 Newtons.
