Answer:

Explanation:
P = Power Output = 1000 W
r = Radius = 35000000 m
= Permittivity of free space = 
c = Speed of light = 
Intensity of Electric radiation is given by

Intensity of Electric radiation is given by

The amplitude of the electric field vector is 
The correct answer should be D. copper
Nickel, cobalt, and iron, produce magnetic fields when electrified while copper does not.
Mass of yellow train, my = 100 kg
Initial Velocity of yellow train, = 8 m/s
mass of orange train = 200 kg
Initial Velocity of orange train = -1 m/s (since it moves opposite direction to the yellow train, we will put negative to show the opposite direction)
To calculate the initial momentum of both trains, we will use the principle of conservation of momentum which
The sum of initial momentum = the sum of final momentum
Since the question only wants the sum of initial momentum,
(100)(8) + (200)(-1) = 600 m/s
Answer:
The bird's speed immediately after swallowing is 4.98 m/s.
Explanation:
Given that,
Mass of bird = 290 g
Speed = 6.2 m/s
Mass of sees = 9.0 g
Speed = 34 m/s
We need to calculate the bird's speed immediately after swallowing
Using conservation of momentum

Put the value into the formula



Hence, The bird's speed immediately after swallowing is 4.98 m/s.
Answer:
The angle above the horizontal at which the pitcher throws the ball determines the distance the ball travels before returning to the height at which it was thrown
Explanation:
The baseball is thrown as a projectile and the range, 'R', of the baseball which is the distance the baseball travels before the height above the ground returns to the initial height is given given as follows;

Where;
R = The range of the baseball = The horizontal distance away from the pitcher the ball reaches
u = The initial velocity with which the baseball was thrown
θ = The angle above horizontal a baseball pitcher throws the ball
g = The acceleration due to gravity ≈ 9.81 m/s²
From the the equation, when θ = 0, sin(θ) = sin(0) = 0 and the ball does not cover any horizontal distance before going lower than the height at which it was thrown, therefore, for the ball to travel further, the angle of launch, θ has to be larger than 0.