What are the 3 equations of motion?

Answer 1

displacement = (final velocity square + initial velocity sq. )/ 2 * acceleration

Answer 2

FIRST EQUATION OF MOTION a=(v-u)/t at = v-u => v-u = at => v= u + at (1) This is Newton's First equation of motion. As you can you see, we can use this equation to calculate the velocity of a body which underwent an acceleration of a m/s for a time period of t seconds, provided we know the initial velocity of the body. Initial velocity i.e. u is the velocity of the body just before the body started to accelerate i.e. the velocity at t=0. SECOND EQUATION OF MOTION velocity = distance traveled / time taken average velocity = (u+v)/2 .: (u+v)/2 = s/t s = [(u+v)/2]t From equation (1) we have v=u+at, substituting this in the above equation for v, we get s = [(u+u+at)/2]t => s = [(2u+at)/2]t => s = [(u + (1/2)at)]t => s = ut + (1/2)at2 - (2) This is Newton's second equation of Motion. This equation can be used to calculate the distance traveled by a body moving with a uniform acceleration in a time t. Again here, if the body started from rest, then we shall substitute u=0 in this equation THIRD EQUATION OF MOTION We start with squaring equation (1). Thus we have v2 = (u+at)2 => v2 = u2 + a2t2 + 2uat => v2 = u2 + 2uat + a2t2 => v2 = u2 + 2a(ut + (1/2)at2) now, using equation 2 we have => v2 = u2 + 2as - (3) As you can see, the above equation gives a relation between the final velocity v of the body and the distance s traveled by the body. Thus, we have the the three Newton's equations of Motion as 1) v= u + at 2) s = ut + (1/2)at2 3) v2 = u2 + 2as

Answer 3

1st equation....................

An object has an initial velocity of 20 ms-1. The object accelerates uniformly for 10 seconds and its final velocity is 45 ms-1. Calculate the acceleration of the object. Answer

Step 1

Gather the information, including the quantity you are asked to find.

initial velocity u = 20 ms-1

final velocity v = 45 ms-1

time t = 10 s

acceleration a = ?

Step 2

Check the units. In this problem all of the units are correct and, as there are no multiples like mm or km, there is no need to change any units.

Step 3

Select the correct relationship. Look at the symbols, what relationship contains the four symbols u, v, t, and a?

v = u + at

Step 4

Carefully substitute the numbers one at a time.

45 = 20 + a × 10

Step 5

Carry out the calculation - you can do this at the side of the page or on your calculator.

45 - 20 = a × 10

25 = a × 10

a = 25/10

= 2.5

Step 6

Write down your answer, including the correct unit.

acceleration = 2.5 ms-2

2nd equation

Question

An electron, released from rest, accelerates uniformly over a distance of 30 mm and reaches a velocity of 600 km s-1. Calculate the acceleration of the electron.

u = 0 ms-1

s = 30 mm = 0.03m

v = 600 kms-1 = 6 × 105 ms-1

a = ?

v2 = u2 + 2as

(6 × 105)2 = 02 + 2 × a × 0.03

a = 6.0 × 1012

Acceleration = 6.0 × 1012 ms-2

3rd equation

uestion

A ball dropped is down a well and hits the water after 4 s. How far is the surface of the water below the top of the well?Answer

u = 0 ms-1

t = 4 s

s = ?

a = g = 9.8 ms-2 (value from data)

s = ut + ½ at2

0 × 4 + ½ × 9.8 × 42

= 78.4

Depth of water surface = 78.4 m

Answer 4

1) v=u+at

2) s=ut+(1/2)at2

3) v2-u2=2as

Answer 5

If you are talking about newton's second law of motion, the three things are : force, mass, and acceleration