How often the particles of a medium vibrate
Answer:

Explanation:
From the exercise we know the final x distance, the angle which the projectile is being released and acceleration of gravity

From the equation of x-position we know that

Solving for 
(1)
Now, if we analyze the equation of y-position we got

At the end of the motion y=0

Knowing the equation for
in (1)


Solving for t
Now, we can solve (1)

Answer:
Explanation:
Before it hits the ground:
The initial potential energy = the final potential energy + the kinetic energy
mgH = mgh + 1/2 mv²
gH = gh + 1/2 v²
v = √(2g (H - h))
v = √(2 * 9.81 m/s² * (0.42 m - 0.21 m))
v ≈ 2.0 m/s
When it hits the ground:
Initial potential energy = final kinetic energy
mgH = 1/2 mv²
v = √(2gH)
v = √(2 * 9.81 m/s² * 0.42 m)
v ≈ 2.9 m/s
Using a kinematic equation to check our answer:
v² = v₀² + 2a(x - x₀)
v² = (0 m/s)² + 2(9.8 m/s²)(0.42 m)
v ≈ 2.9 m/s
Answer:
P = 75 W
Explanation:
given,
Distance, L = 8 m
Force,F = 150 N
Time, t = 16 s
Work by the climber
Work done = Force x displacement
W = F. L
W = 150 x 8
W = 1200 J
We know,


P = 75 W
Hence, Power climber is using to climb is equal to 75 W.
Answer:
<h2>
15m/s</h2>
Explanation:
The equation for a traveling wave as expressed as y(x, t) = A cos(kx −
t) where An is the amplitude f oscillation,
is the angular velocity and x is the horizontal displacement and y is the vertical displacement.
From the formula;
where;

Before we can get the transverse speed, we need to get the frequency and the wavelength.
frequency = 1/period
Given period = 2/15 s
Frequency = 
frequency = 1 * 15/2
frequency f = 15/2 Hertz
Given wavelength
= 2m
Transverse speed 

Hence, the transverse speed at that point is 15m/s