A flea walking along a ruler moves from the 45 cm mark to the 27 cm mark. It does this in 3 seconds. What is the speed? What is
1 answer:
Answer:
Speed= 6cm/s and velocity= 6cm/s in the negative direction
Explanation:
the change in position is from 45cm to 27 cm (moving towards the negative x direction)
And the change in time:
Now we must define the difference between speed and velocity:
Speed is a scalar quantity, which means that it is a number. Velocity is also a number but you must also indicate the direction of the movement.
Thus, the speed is:
An the velocity is:
6cm/s in the negative direction
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Answer:
(a):
(b):
(c):
(d):
(e):
Explanation:
Given, the position of the particle along the x axis is
The units of terms and
should also be same as that of x, i.e., meters.
The unit of t is seconds.
(a):
Unit of
Therefore, unit of
(b):
Unit of
Therefore, unit of
(c):
The velocity v and the position x of a particle are related as
(d):
The acceleration a and the velocity v of the particle is related as
(e):
The particle attains maximum x at, let's say, , when the following two conditions are fulfilled:
Applying both these conditions,
For ,
Since, c is a positive constant therefore, for ,
Thus, particle does not reach its maximum value at
For ,
Here,
Thus, the particle reach its maximum x value at time
Answer:
Explanation:
From work energy theorem
Work done by all forces = Change in kinetic energy
Lets take
m= mass of object
h=height from the ground surface
initial velocity of object = 0 m/s
The final velocity of object is v
Work done by gravitational force = m g . h
The final kinetic energy = 1/2 m v²
So
Work done by all forces = Change in kinetic energy
m g h = 1/2 m v² - 0
v² = 2 g h