The answer should be B. According to the conservation of energy, the energy cannot be created nor destroyed, but it can be transformed. Since the object is moving down, that means its height is decreasing, causing the potential energy decreasing and the kinetic energy increasing to fulfill the conservation law.
The force acting on his feet.
Answer:
it makes our work easy and
time saving
it multiply our force applied
it complete our work with high efficiency
by using this,less effort is required for the work.
The moment of inertia of a point mass about an arbitrary point is given by:
I = mr²
I is the moment of inertia
m is the mass
r is the distance between the arbitrary point and the point mass
The center of mass of the system is located halfway between the 2 inner masses, therefore two masses lie ℓ/2 away from the center and the outer two masses lie 3ℓ/2 away from the center.
The total moment of inertia of the system is the sum of the moments of each mass, i.e.
I = ∑mr²
The moment of inertia of each of the two inner masses is
I = m(ℓ/2)² = mℓ²/4
The moment of inertia of each of the two outer masses is
I = m(3ℓ/2)² = 9mℓ²/4
The total moment of inertia of the system is
I = 2[mℓ²/4]+2[9mℓ²/4]
I = mℓ²/2+9mℓ²/2
I = 10mℓ²/2
I = 5mℓ²
