Answer:
The speed of the plank relative to the ice is:

Explanation:
Here we can use momentum conservation. Do not forget it is relative to the ice.
(1)
Where:
- m(g) is the mass of the girl
- m(p) is the mass of the plank
- v(g) is the speed of the girl
- v(p) is the speed of the plank
Now, as we have relative velocities, we have:
(2)
v(g/b) is the speed of the girl relative to the plank
Solving the system of equations (1) and (2)



I hope it helps you!
Answer:
Acoustic microstreaming
Explanation:
Acoustic microstreaming is the swirling effect produced by water stream confined in a spaced of a periodontal pocket.
- It is the movement of water in a particular direction as a result of mechanical pressure within the fluid body.
- They are often used in dental procedures to remove particulates from the teeth.
- It mostly relies on the properties of sound waves to achieve this goal
The correct answer is B. Fuse.
Fuses were commonly used in houses up to recent ages, when circuit breakers became the more popular options, as they don't have to be changed every time they melt, since they don't melt.
Answer:
The electric field is directed toward the electron and has a magnitude of
.
Explanation:
An electric field is define as the surrounding of charges which exert a force on each other and this force can be attractive or repulsive depends on the charge.
In the given case electron is given and the magnitude of charge on electron is 
Electric field can be represented as,

Here, r is the distance between the point ande charge, k is the electric field constant and Q is the charge.
In the given question an electron is given so electric field will be,

As we know that electric field start from the positive charge and vanish in the negative charge.
So, here the electric field will be
and it is directed toward the electron because of negative charge on the electron.
Answer:
+5m/s
Explanation:
When doing the math we figure out that e is going to be slowing down at -4m/s² for 5 seconds. In total he is slowing down -20m/s which we take from the total speed of +25m/s to get his current new speed.