Answer:
option (A) - false
option (B) - true
option (C) - true
option (D) - true
option (E) - true
option (F) - true
Explanation:
The sound waves are mechanical waves that means they need a medium to travel.
The light waves are non mechanical waves it means they do not need a medium to travel.
Sound cannot travel trough vacuum.
Sound can travel through air and water.
Light can travel trough vacuum and in air and in water.
Answer
given,
mass of the drop, m = 0.0014 g
speed of the drop, u = 8.1 m/s
a) Change in momentum is equal to impulse
final velocity of the drop, v = 0 m/s
J = m ( v - u )
J = 0.0014 x 10⁻³ x ( 0 - 8.1 )
J = -1.134 x 10⁻⁵ kg.m/s
impulse of the roof = - J = 1.134 x 10⁻⁵ kg.m/s
b) time, t = 0.37 m s
impact of force = ?
we know
J = F x t
1.134 x 10⁻⁵ = F x 0.37 x 10⁻³
F = 0.031 N
the magnitude of the force of the impact is equal to F = 0.031 N
Answer: Because between the Earth and Sun there is vacuum
There are three ways in which heat is transmitted:
1. By Conduction, when the transmission is by the direct contact.
2. By Convection, heat transfer in fluids (like water or the air, for example).
3. By<u> Radiation</u>, by the electromagnetic waves (<u>they can travel through any medium and in vacumm</u>)
.
So, the space between the Earth and the Sun is vacuum, this means the energy cannot be transmitted by convection, nor conduction. It must be transmitted by electromagnetic waves that are able to travel with or without a medium, and this is called <u>radiation</u>.
Answer:
The recoil velocity of the projectile is 0.0025m/s
Explanation:
Given:
Mass of the projectile =0.005kg
Mass of the launcher = 1500kg
Velocity = 750 m/s.
To Find:
The recoil velocity of the projectile = ?
Solution:
The recoil velocity is the obtained by dividing the "recoil momentum" by the "mass of the recoil body". The recoil momentum is equal to the momentum of the other body.
The momentum of the other body is equal to it mass times its velocity.
Lets find the recoil momentum,
Recoil momentum = mass of the projectile X velocity
Recoil momentum =
Recoil momentum = 3.75
Now Recoil Velocity,
Recoil Velocity = 
Recoil Velocity = 
Recoil Velocity = 0.0025m/s