Answer:
The number of crates is 84580.
Explanation:
mass, m = 30 kg
height, h = 0.9 mm
Power, P = 0.5 hp = 0.5 x 746 W = 373 W
time, t = 1 minute = 60 s
Let the number of crates is n.
Power is given by the rate of doing work.

Answer:
the correct answer is C
Explanation:
When we express that the scale is 1:30 we mean that the objects of the realization are reduced by a factor of 30 in the graph, for example a distance of 30 cm in the graph is represented by a distance of 1 cm.
Therefore something that in the graph has n value to bring it to real size must be multiplied by the scale.
Applying this to our case if there is
10 boulder on the chart
in reality there are #_boulder = 10 30
#_boulder = 300 boulder
so the correct answer is C
Answer:
1. What type of wave is sound?
2.Does sound need a medium to travel through?
3. What are the properties of sound waves?
Explanation:
1. The type of waves sound are is mechanical waves.
2. Sound needs a solid, liquid or gas (material medium) to travel through.
3. I believe they are wavelength, amplitude, frequency, time period and velocity.
I apologize if it is incorrect-
I hope it helps! Have a great day!
Anygays-
Answer:
Explanation:
correct options
a ) Their electrical potential energy keeps decreasing
Actually as they move apart , their electrical potential energy decreases due to increase of distance between them and kinetic energy increases
so a ) option is correct
b ) Their acceleration keeps decreasing
As they move apart , their mutual force of repulsion decreases due to increase of distance between them so the acceleration decreases .
c ) c. Their kinetic energy keeps increasing
Their kinetic energy increases because their electrical potential energy decreases . Conservation of energy law will apply .