Answer:
Approximately 
. (Assuming that 
, and that the tabletop is level.)
Explanation:
Weight of the book:
.
If the tabletop is level, the normal force on the book will be equal (in magnitude) to weight of the book. Hence, 
.
As a side note, the 
and 
on this book are not equal- these two forces are equal in size but point in the opposite directions.
When the book is moving, the friction 
on it will be equal to
, the coefficient of kinetic friction, times
, the normal force that's acting on it.
That is:
.
Friction acts in the opposite direction of the object's motion. The friction here should act in the opposite direction of that 
applied force. The net force on the book shall be:
.
Apply Newton's Second Law to find the acceleration of this book:
.
1. Millions of gallons of water are wasted by households in America on a yearly basis as a result of wastage of water in the laundry rooms. There are many ways by which water can be conserved in the laundry room, these include:
1. Using a high efficiency washing machine.
2. Choosing the right load sizes and cycles when using washing machines.
3. Wearing clothes more than once before washing them.
4. Collection of grey and rain water.
5. Treat difficult stains before washing them.
2. Using a high efficiency machine will ensure that water is used efficiently. A high efficiency washing machine uses much less water and save about 6,000 gallons of water for an average family on a yearly basis according to Environmental Protection Agency.
Grey water refers to water that have used once. Water that has been used for washing clothes or bathing can be collected again, recycle and use for some household needs such as gardening, flushing of toilet, etc. Water tanks can also be installed to collect rain water which can be used for washing clothes. This will have positive effect on household overall water consumption.
Not at all. Density on its own is not sufficient
In the field of electromagnetism, when two charged plates that are situated opposite to each other by a certain distance, it forms an energy called the electric field. This energy is due to the difference in potential energy with respect to distance. Thus,
E = V/d
However, the voltage in volts is energy per coulomb. Thus,
V = (8x10-17 J/electron)*(1electron/1.60218x10^-19 C)
V = 499.32 volts
Therefore,
E = 499.32 volts /2.5 m
E = 199.73 N/C
The electric field that caused the change in potential energy is equal to 199.73 Newtons per Coulomb.
Answer:
35 m
0.56 m/s west
Explanation:
A) Total distance is the length of the path taken.
30 m + 5 m = 35 m
B) Velocity is displacement over time. Displacement is the difference between the final position and the initial position.
If west is -x, and east is +x, then:
Δx = -30 m + 5 m
Δx = -25 m
v = Δx / t
v = -25 m / 45 s
v = -0.56 m/s
v = 0.56 m/s west
