Electromagnetic waves are usually transverse waves whilst sound wave are longitudinal waves. Furthermore, electromagnetic waves do not require a medium to travel in unlike sound waves which needs solid, liquid or gas mediums.
Answer:
The frictional force acted on mass, m = 7.5 kg
Explanation:
Given data,
The acceleration of the box, a = 2 m/s²
The force acting on the box, F = 15 N
The mass of the box, m = ?
The force is defined as the product of mass and acceleration.
F = m x a newton
Therefore,
m = F / a
= 15 / 2
= 7.5 kg
Hence, the frictional force acted on mass, m = 7.5 kg
<span>LOCATION Z, because it is only 2 away from the coast.
The rest are farther inland
hope this helps</span>
Answer:
A. 40 cm
Explanation:
For a curved mirror, the focal length is twice the radius of curvature of the mirror. In formula:
where
f is the focal length
R is the radius of curvature
The concave mirror in this problem has a radius of curvature of
R = 20 cm
so, its focal length is
Answer:
A = 0.22 m
Explanation:
The spring with the block and the pebble forms an oscillatory system, this system is described by the expression
x = A cos (wt + φ)
w = √ (k / m).
The data they give us is the amplitude of the movement (A = 10 cm), the oscillation mass is equal to the block mass plus the mass of the pebble
m = m + M
m = 0.031 + 0.108
m = 0. 139 kg
To find the spring constant let's use Hooke's law
F = k X
The force is the weight of the pebble and the additional elongation is x = 4.9 cm, let's calculate
k = F / x
k = mg / x
k = 0.031 9.8 / 0.049
k = 6.2 N / m
Let's look for angular velocity
w = √ (6.2 / 0.139)
w = 6,670 rad / s
Let's write the oscillation equation with this data
x = 0.10 cos (6,670 t)
For the pebble to remain in contact with the block, the acceleration of the spring system plus block with pebble must be less than the acceleration of gravity in the descending oscillation
Let's look for system acceleration
a = d²x / dt²
dx / dt = - A w sin (wt + Ф)
d²x / dt² = - A w² cos (wt+Ф)
To find the maximum value cos (wt) = ±1
g = A w²
A = g / w²
A = 9.8 / 6.67²
A = 0.22 m
When the amplitude of the oscillation exceeds this value the pebble is delayed with respect to the block