Answer:

Explanation:
Given that,
The radius of sphere, r = 5 cm = 0.05 m
Net charge carries, q = 7.5 µC = 7.5 × 10⁻⁶ C
We need to find the surface charge density on the sphere. Net charge per unit area is called the surface charge density. So,

So, the surface charge density on the sphere is
.
Complete Question
The complete question is shown on the first uploaded image
Answer:
The temperature change is 
Explanation:
From the question we are told that
The velocity field with which the bird is flying is 
The temperature of the room is 
The time considered is t = 10 \ seconds
The distance that the bird flew is x = 1 m
Given that the bird is inside the room then the temperature of the room is equal to the temperature of the bird
Generally the change in the bird temperature with time is mathematically represented as
![\frac{dT}{dt} = -0.4 \frac{dy}{dt} -0.6\frac{dz}{dt} -0.2[2 * (5-x)] [-\frac{dx}{dt} ]](https://tex.z-dn.net/?f=%5Cfrac%7BdT%7D%7Bdt%7D%20%3D%20-0.4%20%5Cfrac%7Bdy%7D%7Bdt%7D%20-0.6%5Cfrac%7Bdz%7D%7Bdt%7D%20-0.2%5B2%20%2A%20%20%285-x%29%5D%20%5B-%5Cfrac%7Bdx%7D%7Bdt%7D%20%5D)
Here the negative sign in
is because of the negative sign that is attached to x in the equation
So
![\frac{dT}{dt} = -0.4v_y -0.6v_z -0.2[2 * (5-x)][ -v_x]](https://tex.z-dn.net/?f=%5Cfrac%7BdT%7D%7Bdt%7D%20%3D%20-0.4v_y%20%20-0.6v_z%20-0.2%5B2%20%2A%20%20%285-x%29%5D%5B%20-v_x%5D)
From the given equation of velocity field



So
substituting the given values of x and t
Answer:
(a) 104 N
(b) 52 N
Explanation:
Given Data
Angle of inclination of the ramp: 20°
F makes an angle of 30° with the ramp
The component of F parallel to the ramp is Fx = 90 N.
The component of F perpendicular to the ramp is Fy.
(a)
Let the +x-direction be up the incline and the +y-direction by the perpendicular to the surface of the incline.
Resolve F into its x-component from Pythagorean theorem:
Fx=Fcos30°
Solve for F:
F= Fx/cos30°
Substitute for Fx from given data:
Fx=90 N/cos30°
=104 N
(b) Resolve r into its y-component from Pythagorean theorem:
Fy = Fsin 30°
Substitute for F from part (a):
Fy = (104 N) (sin 30°)
= 52 N
Answer: the brand of paper towel
Explanation: the independent variable is the one you control in an experiment. the dependent variable would be the amount of water in the paper towel
Answer: 51841.5 Watts
Explanation: Using the kinematic equation for the final velocity for a constant acceleration we have:
Vf=Vi+a*t
replacing the values the results is
a=(Vf-Vi)/t= (30.55 m/s-19.44 m/s)/5s= 2.22 m/s^2
Remenber that to convert the speed in Km/h to m/s we have to multiplier by the factor 0.277.
Finally to calculate the increment of power get the final velocity we have to use Neton second law to determine the Force applied to the car.
F=m* a=2100 Kg* 2.22 m/s^2= 4666.2 N
Then increment power to accelerate is given by:
ΔPower= Force* Δ velocity= 4666.2 N* 11,11 m/s= 51841.5 Watts