A variable force of 6x−2 pounds moves an object along a straight line when it is x feet from the origin. Calculate the work done
in moving the object from x = 1 ft to x = 18 ft. (Round your answer to two decimal places.) ft-lb
1 answer:
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Answer
Work done will be and it will be positive
Explanation:
We have given charge
We have to find work done in moving the charge from 15 volt to 8 volt
Let
So potential difference
We know that work done , here Q is charge and V is potential difference
So work done
It will be positive work done because work is done in moving charge from higher potential to lower potential
Answer:
20J
Explanation:
In a collision, whether elastic or inelastic, momentum is always conserved. Therefore, using the principle of conservation of momentum we can first get the final velocity of the two bodies after collision. This is given by;
m₁u₁ + m₂u₂ = (m₁ + m₂)v ---------------(i)
Where;
m₁ and m₂ are the masses of first and second objects respectively
u₁ and u₂ are the initial velocities of the first and second objects respectively
v is the final velocity of the two objects after collision;
From the question;
m₁ = 2.0kg
m₂ = 8.0kg
u₁ = 5.0m/s
u₂ = 0 (since the object is initially at rest)
<em>Substitute these values into equation (i) as follows;</em>
(2.0 x 5.0) + (8.0 x 0) = (2.0 + 8.0)v
(10.0) + (0) = (10.0)v
10.0 = 10.0v
v = 1m/s
The two bodies stick together and move off with a velocity of 1m/s after collision.
The kinetic energy(KE₁) of the objects before collision is given by
KE₁ = m₁u₁² +
m₂u₂² ---------------(ii)
Substitute the appropriate values into equation (ii)
KE₁ = ( x 2.0 x 5.0²) + (
x 8.0 x 0²)
KE₁ = 25.0J
Also, the kinetic energy(KE₂) of the objects after collision is given by
KE₂ = (m₁ + m₂)v² ---------------(iii)
Substitute the appropriate values into equation (iii)
KE₂ = ( 2.0 + 8.0) x 1²
KE₂ = 5J
The kinetic energy lost (K) by the system is therefore the difference between the kinetic energy before collision and kinetic energy after collision
K = KE₂ - KE₁
K = 5 - 25
K = -20J
The negative sign shows that energy was lost. The kinetic energy lost by the system is 20J
The momentum of an object is the product between the mass m of the object and its velocity:
The truck in our problem has momentum equal to
and a mass of
so, if we re-arrange the previous formula, we can use these data to find the velocity of the truck:
The truck in our problem has momentum equal to
and a mass of
so, if we re-arrange the previous formula, we can use these data to find the velocity of the truck: