Solution :
Using the Gauss law, the electric field intensity of a sphere is given by :
[tex]$E. 4 \pi r^2 = \frac{Q_{enc}}{\epsilon_0}$[/tex]
[tex]$E = \frac{Q_{enc}}{4 \pi r^2 \epsilon_0}$[/tex]
Now the enclosed charge inside the sphere (r<a) is
[tex]$Q_{enc}= \rho V$[/tex]
[tex]$Q_{enc}= \rho \left( \frac{4}{3} \pi r^3 \right)$[/tex]
Hence, the electric field intensity becomes as follows :
[tex]$E= \frac{\rho \left(\frac{4}{3} \pi r^3\right)}{4 \pi \epsilon_0 r^2}$[/tex]
[tex]$E =\frac{\rho r}{3 \epsilon_0}$[/tex]
Thus, the electric field inside the sphere is given by :
[tex]$\vec {E} = \frac{\rho \vec{r}}{3 \epsilon_0}$[/tex]
A highway speed limit is posted as 90 km/hr. Is this average speed or instantaneous speed? Explain your answer.
Explain how are position time, velocity, and acceleration related to each
other?
a girl pushes her little brother down a snowy hill on a sled and he rides quickly to the bottom of the hill
which one of Newton's Laws is this
Answer:
Newton's First Law of Motion.
Explanation:
Inertia can be defined as the tendency of an object or a body to continue in its state of motion or remain at rest unless acted upon by an external force.
In physics, Sir Isaac Newton's First Law of Motion is known as law of inertia and it states that, an object or a physical body in motion will continue in its state of motion at continuous velocity (the same speed and direction) or, if at rest, will remain at rest unless acted upon by an external force.
In this scenario, a girl pushes her little brother down a snowy hill on a sled and he rides quickly to the bottom of the hill. The push from the little boy's sister is the external force acting on him and consequently, causing him to be in motion down the snowy hill.
Romeo traveled by a 900 kg horse from Manitua to Verona accelerating at the rate of 20 km/hr. With what force is Romeo moving at?
Answer:
Force(Romeo moving) = 5,000 N
Explanation:
Given:
Mass of horse = 900 kg
Acceleration = 20 km/hr
Find:
Force(Romeo moving)
Computation:
Acceleration = 20 km/hr
Acceleration in m/s = 20 / 3.6 = 5.555556 m/s²
Force = m x a
Force(Romeo moving) = 900 x 5.555556
Force(Romeo moving) = 5,000 N
The speed of the wooden bar is changed so that the bar hits the water fewer times each second.
What happens to the frequency of the waves produced?
A. Increases
B. Does not change
C. Decreases
Answer:
c - the frequency of the waves decreases
An object of mass m is placed on Spring A, which is compressed by distance x. The spring is released and the velocity of the pushed object as it leaves the spring is measured. The experiment is repeated with the same object on Spring B, which is compressed by the same distance x. The object travels faster when pushed by Spring B. What can be concluded?
A .Spring A had a higher elastic potential energy than Spring B.
B. Spring A's spring constant is higher than Spring B's.
C. Spring A's spring constant is lower than Spring B's.
D. Spring A has more mass than Spring B.
Answer:
C
Explanation:
please help! you are amazing! brainliest too!
NASA helps fund science education.
Which statement about scientific knowledge is false?
A. Understanding science can help people make wiser purchases.
B. People with more knowledge of science are always healthier.
C. People with college degrees in science often earn high salaries.
D. Science education can help people understand the universe.
Answer:
I think its B and I don't know why my words are like this
Explanation:
A car has a mass of 1500 kg and accelerates at a rate of 15 m/s^. What was the force applied?
Answer:
22500N
Explanation:
Given parameters:
Mass of the car = 1500kg
Acceleration = 15m/s²
Unknown:
Force applied = ?
Solution:
From Newton's second law of motion:
Force = mass x acceleration
So
Force = 1500 x 15 = 22500N
While driving his sports car at 20.0 m/s through a residential neighborhood, Royston
comes up behind a slow-moving grandma and decides to pass her on the left. If
Royston can accelerate at 6.00 m/s2, how long will it take for him to reach a velocity of
30.0 m/s?
Answer:
1.67s
Explanation:
Given parameters:
Initial velocity = 20m/s
Acceleration = 6m/s²
Final velocity = 30m/s
Unknown:
Time taken = ?
Solution:
Acceleration is the rate of change of velocity with time. It is mathematically expressed as;
Acceleration = [tex]\frac{v - u }{t}[/tex]
v is the final velocity
u is the initial velocity
t is the time taken
6 =[tex]\frac{30 - 20}{t}[/tex]
6 = [tex]\frac{10}{t}[/tex]
10 = 6t
t = 1.67s
