Complete Question
A small metal sphere, carrying a net charge q1=−2μC, is held in a stationary position by insulating supports. A second small metal sphere, with a net charge of q2= -8μC and mass 1.50g, is projected toward q1. When the two spheres are 0.80m apart, q2 is moving toward q1 with speed 20ms−1. Assume that the two spheres can be treated as point charges. You can ignore the force of gravity.The speed of q2 when the spheres are 0.400m apart is.
Answer:
The value 
Explanation:
From the question we are told that
The charge on the first sphere is 
The charge on the second sphere is 
The mass of the second charge is 
The distance apart is 
The speed of the second sphere is 
Generally the total energy possessed by when
and
are separated by
is mathematically represented

Here KE is the kinetic energy which is mathematically represented as

substituting value


And U is the potential energy which is mathematically represented as

substituting values


So


Generally the total energy possessed by when
and
are separated by
is mathematically represented

Here
is the kinetic energy which is mathematically represented as

substituting value


And
is the potential energy which is mathematically represented as

substituting values


From the law of energy conservation

So


Answer:
3.258 m/s
Explanation:
k = Spring constant = 263 N/m (Assumed, as it is not given)
x = Displacement of spring = 0.7 m (Assumed, as it is not given)
= Coefficient of friction = 0.4
Energy stored in spring is given by

As the energy in the system is conserved we have

The speed of the 8 kg block just before collision is 3.258 m/s
Water is a very unique substance because it can exist in all three phases of matter (solid, liquid, gas) within the normal temperature ranges found on Earth. When one observes the phase of matter of water, one observes a property of matter.
Answer:
The coefficient of performance for the cycle is 2.33.
Explanation:
Given that,
Output energy 
Work done 
We need to calculate the coefficient of performance
Using formula of the coefficient of performance

We need to calculate the 

Put the value into the formula



Now put the value of
into the formula of COP


Hence, The coefficient of performance for the cycle is 2.33.
Answer:
We want to describe how to graph a linear equation.
Explanation:
The given equation is:
y = -4x - 1
a) To graph it, we need to find two points that belong to the line, then we graph the points, and then we connect them with a line.
To get the points, we just need to evaluate the function in two different values of x.
for x = 0
y = -4*0 - 1 = -1
So we have the point (0, -1)
for x = 1
y = -4*1 - 1 = -5
So we have the point (1, - 5)
Now we just need to find these two points and connect them with a line, the graph can be seen below.
b) To check if the graph is correct we can see two things:
in y = -4*x - 1
The y-intercept is -1, this means that the graph should intersect the y-axis at y = -1
The slope is -4, this means that for each unit increase on x, we should see that the y-value decreases by 4.
Checking those two things we can see if our graph is correct or not.
pls give brainliest!