15 yellow bottles.
3 + 7 = 10
50 / 10 = 5
3 x 5 = 15
Scientists believe that thesolar system<span> was </span>formed<span> when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space which squeezed the cloud of gas and dust.</span>
Answer
Gravitational force is between two object caused by energy in mass. Here when you are in a mine the radius of the earth in case of calculating gravity is reduced to the length between you and the center.
This means the mass of earth is decreasing even though the distance is decreasing. Relative to the decrease in distance squared the decrease in the mass of the second object(earth) is more. As a result your weight decreases.
Answer:
Frequency doubles.
Explanation:
Frequency doubles because Wavelength and Frequency are inversely proportional. That means if one decreases the other one increases. So, if wavelength is half, frequency is the opposite, doubles.
Answers:
1) 
2) 
Explanation:
1) Acceleration 
is defined as the variation of Velocity 
in time 
:
(1)
A body also has acceleration when it changes its direction.
In this case we have a bus with a velocity of 60m/s to the east, that accelerates in a time 10s. So, we have to find the bus's acceleration:
(2)
(3) This is the bus's accelerration
2) Now we have a car that accelerates 
to the west in order to reach a speed of 
in the same direction, and we have to find the time it takes to the car to reach that velocity.
Therefore we have to find from (1):
(4)
(5)
Finally:
(6)
