Joe balances a stationary coin on the the tip of his finger 20 cm from the top of the table. How much work is Joe doing?
1 answer:
The work done by Joe is 0 J.
<u>Explanation</u>:
When a force is applied to an object, there will be a movement because of the applied force to a certain distance. This transfer of energy when a force is applied to an object that tends to move the object is known as work done.
The energy is transferred from one state to another and the stored energy is equal to the work done.
W = F . D
where F represents the force in newton,
D represents the distance or displacement of an object.
Force = 0 N, D = 20 cm = 0.20 m
W = 0 0.20 = 0 J.
Hence the work done by Joe is 0 J.
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Answer:
The acceleration of the object during the motion is 1.6 m/s²
Explanation:
Lets explain how to solve the problem
An object moving on the x-axis with a constant acceleration
Its distance increases 80 meter in 5 seconds
Its final velocity is 20 m/s
We need to find the acceleration of the object during this motion
To solve the problem we will use two equations:
<u><em>First:</em></u> , where s is the displacement, u is the
initial velocity, t is the time, and a is the acceleration
<u><em>Second:</em></u> v = u + at, where v is the final velocity
s = 80 , t = 5 , v = 20 we have two missing a and u, so we will use the
system of equations to find them
Substitute s, t in the first equation
80 = 5u + 12.5a
5u + 12.5a = 80 ⇒ (1)
Substitute V and t in the second equation
20 = u + a(5)
20 = u + 5a
u + 5a = 20 ⇒ (2)
Lets solve equations (1) and (2)
Multiply equation (2) by -5 to eliminate u
-5u - 25 a = -100 ⇒ (3)
Add equations (1) and (3)
-12.5 a = -20
Divide both sides by -12.5
a = 1.6
<em>The acceleration of the object during the motion is 1.6 m/s²</em>