C. Electromagnetic waves do not always need a medium to travel.
Since they are transverse waves they do not need a material medium.
Answer:
0.07142 m/s in the opposite direction of the bullet
Explanation:
= Mass of rifle = 70 kg
= Mass of bullet = 0.01 kg
= Velocity of rifle
= Velocity of bullet = 500 m/s
As the momentum of the system is conserved

The recoil velocity of the rifle is -0.07142 m/s
The negative sign shows the opposite direction of the rifle.
<h2>
Answer: 12 s</h2>
Explanation:
The situation described here is parabolic movement. However, as we are told <u>the instrument is thrown upward</u> from the surface, we will only use the equations related to the Y axis.
In this sense, the main movement equation in the Y axis is:
(1)
Where:
is the instrument's final position
is the instrument's initial position
is the instrument's initial velocity
is the time the parabolic movement lasts
is the acceleration due to gravity at the surface of planet X.
As we know
and
when the object hits the ground, equation (1) is rewritten as:
(2)
Finding
:
(3)
(4)
(5)
Finally:

The net charge of the electron will be there because there is no exponents there
Answer:
A) 10 m/s
Explanation:
We know that according to conservation of momentum,
m1v1 + m2v2 = m1u1 + m2u2 ..............(equation 1)
where m1 and m2 are masses of two bodies, v1 and v2 are initial velocity before collision and u1 and u2 are final velocities after collision respectively.
From the given data
If truck and car are two bodies
truck : m1 = 2000 Kg v1 = 5 m/s u1 = 0
car : m2 = 1000 kg v2 = 0 u2 = ?
final velocity of truck and initial velocity of car are static because the objects were at rest in the respective time.
substituting the values in equation 1, we get
(2000 x 5) + 0 = 0 + (1000 x u2)
u2 =
x 5
= 10 m/s
Hence after collision, car moves at a velocity of 10 m/s