Answer:
Find answers below.
Explanation:
Given the following data;
Voltage = 220V
Current = 15 A
a. To find the power;
Power = current * voltage
Power = 15 * 220
Power = 3300 Watts
b. To find the energy;
Time = 8 hours = 60 * 60 * 8 = 28800 seconds
Energy = power * time
Energy = 3300 * 8
Energy = 26400
Energy = 26.4 Kwh
c. Cost = 13 cents
Cost = 13 * 31 * 26.4
Cost = 106392 cents
Answer:
Friction between the box and the floor is 25N to the left
Explanation:
There are two forces acting on the box along the horizontal direction:
- The force of push applied by the worker, in the forward direction, F
- The force of friction,
, acting in the opposite direction (backward)
So the net force acting on the box is

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

And so

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

Therefore we have:

Which means

And since we are told that

This means that the force of friction is also 25 N:

Answer:
1028 slits/mm
Explanation:
We are given that
Wavelength of light, 
1nm=

n=1
We have to find the number of slits per mm are marked on the grating.
We know that

Using the formula



1m=
mm

Number of slits=
Number of slits=
/mm
Number of slits=1028/mm
Hence, 1028 slits/mm are marked on the grating.
Answer: The control group is the part where you see what happens when you change a variable you want to study/examine. Basically, you need the control group because you need something to see what happens when you change something.
Hope this Helps! :))))