Answer:
(a) 81.54 N
(b) 570.75 J
(c) - 570.75 J
(d) 0 J, 0 J
(e) 0 J
Explanation:
mass of crate, m = 32 kg
distance, s = 7 m
coefficient of friction = 0.26
(a) As it is moving with constant velocity so the force applied is equal to the friction force.
F = 0.26 x m x g = 0.26 x 32 x 9.8 = 81.54 N
(b) The work done on the crate
W = F x s = 81.54 x 7 = 570.75 J
(c) Work done by the friction
W' = - W = - 570.75 J
(d) Work done by the normal force
W'' = m g cos 90 = 0 J
Work done by the gravity
Wg = m g cos 90 = 0 J
(e) The total work done is
Wnet = W + W' + W'' + Wg = 570.75 - 570.75 + 0 = 0 J
Answer:
a) Total mass form, density and axis of rotation location are True
b) I = m r²
Explanation:
a) The moment of inertia is the inertia of the rotational movement is defined as
I = ∫ r² dm
Where r is the distance from the pivot point and m the difference in body mass
In general, mass is expressed through density
ρ = m / V
dm = ρ dV
From these two equations we can see that the moment of inertia depends on mass, density and distance
Let's examine the statements, the moment of inertia depends on
- Linear speed False
- Acceleration angular False
- Total mass form True
- density True
- axis of rotation location True
b) we calculate the moment of inertia of a particle
For a particle the mass is at a point whereby the integral is immediate, where the moment of inertia is
I = m r²
The planets revolving around the sun, The moon revolving around the Earth.
