Answer:
option a
Explanation:
Light is an electromagnetic wave which can travel in vacuum as well as any medium. The speed of light is maximum in vacuum. The electromagnetic wave travels by oscillating electric and magnetic field to the direction of motion of wave.
On the other hand, sound waves are mechanical waves which can only travel in a medium as they can only move forward by oscillating material particles.
Thus, the student should conclude option a.
Answer:
A. 1.4 m/s to the left
Explanation:
To solve this problem we must use the principle of conservation of momentum. Let's define the velocity signs according to the direction, if the velocity is to the right, a positive sign will be introduced into the equation, if the velocity is to the left, a negative sign will be introduced into the equation. Two moments will be analyzed in this equation. The moment before the collision and the moment after the collision. The moment before the collision is taken to the left of the equation and the moment after the collision to the right, so we have:
where:
M = momentum [kg*m/s]
M = m*v
where:
m = mass [kg]
v = velocity [m/s]
where:
m1 = mass of the basketball = 0.5 [kg]
v1 = velocity of the basketball before the collision = 5 [m/s]
m2 = mass of the tennis ball = 0.05 [kg]
v2 = velocity of the tennis ball before the collision = - 30 [m/s]
v3 = velocity of the basketball after the collision [m/s]
v4 = velocity of the tennis ball after the collision = 34 [m/s]
Now replacing and solving:
(0.5*5) - (0.05*30) = (0.5*v3) + (0.05*34)
1 - (0.05*34) = 0.5*v3
- 0.7 = 0.5*v
v = - 1.4 [m/s]
The negative sign means that the movement is towards left
B: Extension Lines! You could have just searched this up on google
It depends, How big is the room. If it was me i would put "High density foam pads" all over the walls in the room, and that would get rid of some sound but put Drywall, or Plasterboard behind the foam pads. That should hopefully get rid of the sound from outside the room, and stop any noise in the background, if your using a mic, for example, a Youtube channel, or Twitch treaming channel. Hope this helps. BYE!!
Answer: Friction stops things from sliding apart. If there was no friction everything would slide to the lowest point. With no friction the only possible movement would be falling to a lower point under gravity.
Explanation: In a frictionless world, more objects would be sliding about, clothes and shoes would be difficult to keep on and it would be very difficult for people or cars to get moving or change direction. Students should be encouraged to consider how dependant their world is on the beneficial action of friction. Humans and other objects will become weightless without gravity. If we have no gravity force, the atmosphere would disappear into space, the moon would collide with the earth, the earth would stop rotating, we would all feel weightless, the earth would collide with the sun, and as a consequence.
