Answer:


Explanation:
k = Coulomb constant = 
Q = Charge
r = Distance = 8 cm
R = Radius = 4 cm
Electric field is given by

Volume charge density is given by

The volume charge density for the sphere is 

The magnitude of the electric field is 
Answer:
A simple pulley is a wheel with a rope that allows you to pull one end and have it lift whatever is on the other end. A modern, common example of this is a crane, often used in construction.
Explanation:
Weight equals mass times gravitational acceleration=400N, so mass=400/9.8=41kg approx.
Answer:
Mg and HCl
Explanation:
Here, we want to get the combination that could be used in the production of the needed hydrogen
An important chemical property of inorganic acids is that when they react with metals, they give off hydrogen gas in conjunction with the formation of a salt
HCl is a mineral acid while Mg is a metallic substance
So the reaction between this metal and the mineral acids will give the needed hydrogen gas to be produced
Answer:
5.25%
Explanation:
From the question given above, the following data were obtained:
Accepted value = 238857 miles
Measured value = 226316 miles
Percentage error =.?
Next, we shall determine the absolute error. This can be obtained as follow:
Accepted value = 238857 miles
Measured value = 226316 miles
Absolute Error =?
Absolute Error = |Measured – Accepted|
Absolute Error = |226316 – 238857|
Absolute Error = 12541
Finally, we shall determine the percentage error. This can be obtained as follow:
Accepted value = 238857 miles
Absolute Error = 12541
Percentage error =.?
Percentage error = absolute error / accepted value × 100
Percentage error
= 12541 / 238857 × 100
= 1254100 / 238857
= 5.25%
Therefore, the percentage error is 5.25%.