Answer:
When the polythene rod is rubbed with the woolen cloth, static electric charges move from the cloth and into the rod. The rod becomes negatively charged as negative charges move from the cloth and into the rod leaving the cloth positively charged as well.
Answer:
the speed of the center of mass stays the same
Explanation:
In a system with no energy loss, momentum is conserved if the mass remains constant. The system described has no change in mass, and energy loss is considered negligible. Hence the product of the total mass and the velocity of its center will be a constant. The center of mass stays the same speed.
Answer:
Because of the speed of the sound.
Explanation:
The first thing that happens in such cases is to take into account the speed of the sound. First, we see that the player hits the ball with the bat, if we are in the stands far enough we will hear the sound of the batting time later, this time depends on the speed of the sound which is equal to 345 [m/s].
Another visible and practical example is a fireworks display, where people nearby immediately hear the explosion. while those at a great distance will be able to see first the explosion followed by the sound.
With the following equation, we can calculate how long it takes to hear a hit or explosion
t = x / v
where:
x = distance [m]
v = sound velocity = 345 [m/s]
t = time [s]
Answer:
F=1.14N j
Explanation:
The magnitude of the magnetic force over a charge in a constant magnetic field is given by the formula:
(|)
In this case v and B vectors are perpendicular between them. Furthermore the direction of the magnetic force is:
-i X k = +j
Finally, by replacing in (1) we obtain:
hope this helps!
