One of the equations of gravity is this:

Where v = final velocity which is 7m/s
u = initial velocity which is 0 for objects falling from a height
g = acceleration due to gravity and it is approximately 10m/s^2. It's a constant so pretty much remember this number. It's positive since the work being done is caused by gravity (in other words, it's falling down). It can also be negative if the work being down is against gravity (in other words, it's going up)
h = height of object
Substitute for the values and you should have something like this



What does a physical map show?
the names of countries, states, and cities
the history of an area
the geographical features of an area
the rest stops and restaurants in an area
Answer:
1. The current will drop to half of its original value.
Explanation:
The problem can be solved by using Ohm's law:

where
V is the voltage across the circuit
R is the resistance of the circuit
I is the current
We can rewrite it as

In this problem, we have:
- the resistance of the circuit remains the same: R' = R
- the voltage is decreased to half of its original value: 
So, the new current will be

so, the current will drop to half of its original value.
Answer:
See the explanation below
Explanation:
Density is defined as the relationship between mass and volume, i.e. the following equation can be used:
density = m/v
where:
density [kg/m^3]
m = mass [kg]
v = volume [m^3]
If we change the volume of a body by reducing its size, its mass will also decrease proportionally with a density as seen in the equation.
m = density*v
To understand this concept more clearly, let's use the following example:
We know that the density of water is equal to 1000 [kg/m^3], that is, 1 cubic meter of water contains 1000 kilograms of water, using the equation.
1000 = m /1
m = 1000*1 = 1000 [kg]
Now if we have 500 kilograms of water, that would pass with the volume so that the density remains constant.
1000 = 500/v
v = 500/1000
v = 0.5 [m^3]
We can see that the volume of water has halved. Since the mass of water was reduced by half. That is, the relationship between mass and volume is proportional to the density of the material or substance.