1. lifts it chest high
The force opposing to this action is the force due to
gravity. Therefore the work done is:
W1 = m g d
where m is mass of the barbell, g is gravity and d is displacement
2. holds it for 30 seconds
Work is a product of force and displacement, since there
is no displacement, therefore work done is zero.
W2 = 0
3. puts it down slowly
If the barbell was dropped, then it would simply be a free
fall. But since it was not, so the work done here is also equal to the weight
of the barbell times displacement:
W3 = m g d
We can see that W1 = W3, and since W2 = 0, therefore the answer
is:
<span>w3 = w1 > w2</span>
Answer:
flux=13.92W/m^2
Explanation:
The heat transfer by conduction consists in the transport of energy through particles that are together, that is to say by means of solids, Newton developed an equation that allows to know the heat transported in a flat plate knowing the cross sectional area A, Thickness L, conductivity K and a temperature difference between the internal and external surface.
Q=KA(t2-t1)/L
To know the heat flux we simply divide both sides of the equation by the area.
Flux=K(t2-t1)/L
where
K=0.029w/mk
L=25mm=0.025m
t2-t1=12 ° C
solving
Flux=(0.029)(12)/(0.025)
flux=13.92W/m^2
Answer:
True.
Explanation:
Defenintion of Muscular Endurance:
The ability of a muscle (or set of muscles) to perform a repeated action without tiring.
Answer:
This is because the acceleration of objects due to gravity is independent of the mass of the object and is constant for all objects, therefore, all objects fall with the same speed.
Explanation:
The weight of an object or force of gravity acting on an object on the surface of earth is a product of its mass and acceleration due to gravity.
Mathematically, w = mg
where, m=mass of the object; g = acceleration due to gravity
Also, from newton's law of gravitation, gravitational force on the object ,F = GMm/r²
where G is the gravitational constant; M is mass of Earth; m is mass of object; r is the distance of separation between the object and the center of mass of the earth which is approximately the radius of earth.
Since the weight of an object is equal to the force of gravitation acting on it
W = F
mg = GMm/r²
g = GM/r²
The expression above is that of the relationship between the force of gravity acting on a body on the earth's surface, the weight of that body and the acceleration due to gravity, g.
It can be seen that the acceleration due to gravity g is independent of the mass of the object. Therefore, the acceleration of objects due to gravity is constant for all objects and all objects fall with the same speed.
Answer:
18750 kg-m/s
Explanation:
Momentum = mass x velocity
