Answer:
The force of gravity pulling downward and the force of the table pushing upwards on the book are of equal magnitude and opposite directions. These two forces balance each other. Yet there is no force present to balance the force of friction. ... Unbalanced forces cause accelerations.
Explanation:
Answer: Liquefaction occurs when the structure of a loose, saturated sand breaks down due to some rapidly applied loading.
As the structure breaks down, the loosely-packed individual soil particles attempt to move into a denser configuration. Liquefaction most often occurs when three conditions are met:
loose, granular sediment or fill
saturation by groundwater
strong shaking
Answer:
500Km
Explanation:
This question is an example of speed, distance, time.
The formula for working out the distance is: 
To work this out you would need to multiply the speed of 200Km/h by the time of 2.5 hours, this gives you 500 Km. This is because the formula to work out the distance is speed * time.
In adittion, if the train is traveling at 200km per hour then that means that over the course of an hour the distance travelled would be 200Km. So, by multiplying the speed by the time you are working out how far it travelled in that given time.
1) Multiply 200 by 2.5.

Speed is a derived term that is the result when distance or displacement is divided by unit time. Speed is a scalar unit which means it only includes magnitude not direction, thus always positive. The answer thus are the three choices given above.
Answer:
9 kg
Explanation:
Momentum is mass times velocity.
p = mv
36 kgm/s = m (4 m/s)
m = 9 kg