Hi there!
Impulse = Change in momentum
I = Δp = mΔv = m(vf - vi)
Where:
m = mass of object (kg)
vf = final velocity (m/s)
vi = initial velocity (m/s)
Begin by converting grams to kilograms:
1 kg = 1000g ⇒ 145g = .145kg
Now, plug in the given values. Remember to assign directions since velocity is a vector. Let the initial direction be positive and the opposite be negative.
I = (.145)(-20 - 17) = -5.365 Ns
The magnitude is the absolute value, so:
|-5.365| = 5.365 Ns
Answer:
4.08 s
Explanation:
Let the passenger took "t" time to catch the train
so in this case the total distance moved by the train + 5 m = total distance moved by the passenger
so we will have
distance moved by train is given as

also the distance moved by passenger

so we will have



t = 4.08 s
Answer:· A model is a description of natural phenomenon that scientists can use to make predictions. A good model is both as accurate as possible and as simple as possible, which makes it not only powerful but also easy to understand. However, no matter how good they are, models will almost always have limitations.
Explanation:
Answer:
Explanation:
Volume of the insulating shell is,

Charge density of the shell is,

Here, 

B)
The electric field is 
For 0 <r<R the electric field is zero, because the electric field inside the conductor is zero.
C)
For R <r <2R According to gauss law

substitute 

D)
The net charge enclosed for each r in this range is positive and the electric field is outward
E)
For r>2R
Charge enclosed is zero, so electric field is zero
Answer:
The volume of the submerged part of her body is 
Explanation:
Let's define the buoyant force acting on a submerged object.
In a submerged object acts a buoyant force which can be calculated as :
ρ.V.g
Where ''B'' is the buoyant force
Where ''ρ'' is the density of the fluid
Where ''V'' is the submerged volume of the object
Where ''g'' is the acceleration due to gravity
Because the girl is floating we can state that the weight of the girl is equal to the buoyant force.
We can write :
(I)
Where ''W'' is weight
⇒ If we consider ρ =
(water density) and
and replacing this values in the equation (I) ⇒


ρ.V.g = 610N
(II)
The force unit ''N'' (Newton) is defined as

Using this in the equation (II) :



We find that the volume of the submerged part of her body is 