Instruction

1

Formulas to find distance if you know time and speed are of the form:

in uniform motion:

S = v*t, where S is distance, v – velocity, t – time;

when uniformly accelerated motion:

S = v0*t + ½a*t2, where S is distance, v0 is initial velocity, a – acceleration, t – time.

in uniform motion:

S = v*t, where S is distance, v – velocity, t – time;

when uniformly accelerated motion:

S = v0*t + ½a*t2, where S is distance, v0 is initial velocity, a – acceleration, t – time.

2

Formulas for calculating speed if you know distance and time:

in uniform motion:

v = S/t where S – distance, v – velocity, t – time;

when uniformly accelerated motion:

v = v0 + a*t where v0 is the initial velocity, a – acceleration, t – time.

in uniform motion:

v = S/t where S – distance, v – velocity, t – time;

when uniformly accelerated motion:

v = v0 + a*t where v0 is the initial velocity, a – acceleration, t – time.

3

The formula to determine the time, if you know the speed and distance have the form:

in uniform motion:

t = S/v, where S is distance, v – velocity, t – time;

when uniformly accelerated motion:

t = (v – v0)/a , where v0 is the initial velocity, a – acceleration, t – time.

in uniform motion:

t = S/v, where S is distance, v – velocity, t – time;

when uniformly accelerated motion:

t = (v – v0)/a , where v0 is the initial velocity, a – acceleration, t – time.

# Advice 2 : How to find average speed

Average

**speed**can be calculated by dividing the distance covered by the body way to spent time with him. But in practice, when solving physics problems it is important to remember some specific nuances.Instruction

1

Calculate the average

**speed**of a body moving uniformly throughout the section of the path. This**speed**calculation is easier because it is not changed on the whole interval**movement**, and is equal to the average speed. You can write it as a formula: Vрд = V CP where Vрд –**speed**of uniform**movement**, and Vav is the average**speed**.2

Calculate the average

**speed**ravnokonechnogo (uniformly accelerated)**motion**at the site, which is necessary to lay down the initial and final**speed**. Divide by two the result, which will be the average**speed**of Yu. You can write it more clearly as a formula: Vav = (VN + V)/2, where VN is the initial**velocity**, and V is finite.3

Take advantage of a special variant of the above formula, if we know the acceleration and initial

**speed**, but not set the final**speed**. Mark acceleration as a ratio of ”a” and have the formula: V = a * t + VN. Hence Vav = (VN + V)/2 = (a * t + VN + VN)/2 = a * t / 2 + VN.4

Convert the above formula if the unknown initial

**speed**, but set the acceleration and final**velocity**:Vav = (VN + V )/2 = (V + V - a * t)/2 = V - a * t / 2.5

Calculate the average

**speed**if the length of the traversed path (S) spent on the passage of time (t) by dividing them. This is the classic formula: Vav = S / t. Remember that you must fully take into account the time, even if the object is stopped during the passage of the plot.Note

If the task does not specify, then the required value is the average ground speed. Under the realized path when calculating understand it is the length of the path along which the body moves. If during the movement of the body to return again to the passed items, then these areas must also be considered and added to the total length of the road.