<span>It’s 2/5 MR^2 where M is mass and R is the radius of the bas</span>
We can solve the problem by using Ohm's law, which states that an Ohmic conductor the following relationship holds:

where

is the potential difference applied to the resistor
I is the current flowing through it
R is the resistance
In our problem, I=4.00 A and

, so the potential difference is
Answer:
Total impulse =
= Initial momentum of the car
Explanation:
Let the mass of the car be 'm' kg moving with a velocity 'v' m/s.
The final velocity of the car is 0 m/s as it is brought to rest.
Impulse is equal to the product of constant force applied to an object for a very small interval. Impulse is also calculated as the total change in the linear momentum of an object during the given time interval.
The magnitude of impulse is the absolute value of the change in momentum.

Momentum of an object is equal to the product of its mass and velocity.
So, the initial momentum of the car is given as:

The final momentum of the car is given as:

Therefore, the impulse is given as:

Hence, the magnitude of the impulse applied to the car to bring it to rest is equal to the initial momentum of the car.
Answer:
(a) charge q=5.33 nC
(b) charge density σ=10.62 nC/m²
Explanation:
Given data
radius r=0.20 m
potential V=240 V
coulombs constant k=9×10⁹Nm²/C²
To find
(a) charge q
(b) charge density σ
Solution
For (a) charge q
As

For (b) charge density
As charge density σ is given as:
σ=q/(4πR²)
σ=(5.333×10⁻⁹) / (4π×(0.20)²)
σ=10.62 nC/m²
Answer:
They have same density
Explanation:
The density of an object is defined as

where
m is the mass of the object
V is its volume
Let's call
and
the mass and the volume of ball C, respectively. Therefore, the density of ball C is:

We know that the volume of ball C is 3 times the volume of ball D, so

And we also know that ball D has 1/3 the mass of ball C:

So, the density of ball D is:

Therefore, the two balls have same density.