Answer:
To minimize the practical errors and improve the accuracy.
Explanation:
- Scientists take several measurements and use the average of all the measured values to minimize the practical errors due to unavoidable circumstances and be close to the true value.
- True value is the actual value of a measured parameter without any error, it is the value which is proposed in the design of a certain object.
- Variations may occur in the measurement due to wear and tear, dust and air pressure. It is almost impossible to create ideal surrounding for the measurement procedure.
Answer:
The time is 133.5 sec.
Explanation:
Given that,
One side of cube = 10 cm
Intensity of electric field = 11 kV/m
Suppose How long will it take to raise the water temperature by 41°C Assume that the water has no heat loss during this time.
We need to calculate the rate of energy transfer from the beam to the cube
Using formula of rate of energy


Put the value into the formula


We need to calculate the amount of heat
Using formula of heat


Put the value into the formula


We need to calculate the time
Using formula of time

Put the value into the formula


Hence, The time is 133.5 sec.
Answer:
C
Explanation:
it transforms electrical energy into mechanical energy.
Answer:
a = w² r
Explanation:
In this exercise, indicate that the wheel has angular velocity w, the worm experiences the same angular velocity if it does not move, and has an acceleration towards the center of the circle, according to Newton's second law, called the centripetal acceleration.
a = v² / r
angular and linear variables are related
v = w r
we substitute
a = w² r
where r is the radius of the wheel