25 kg
Explanation:
we can calculate the mass of the crate by using the Newton's second law:

where
F is the force acting on the crate
m is the mass
a is the acceleration
In this problem,
and
, so we can re-arrange the equation above to calculate the mass of the crate:

When a gas is compressed, its particles are pushed closer together so it is more dense.
Answer:
(a). Energy is 64,680 J
(b) velocity is 51.43m/s
(c) velocity in mph is 115.0mph
Explanation:
(a).
The potential energy
of the payload of mass
is at a vertical distance
is
.
Therefore, for the payload of mass
at a vertical distance of
, the potential energy is


(b).
When the payload reaches the bottom of the shaft, all of its potential energy is converted into its kinetic energy; therefore,




(c).
The velocity in mph is


Answer:
The no of revolutions rotor turn before coming to rest is 1,601.1943 and time taken is equal to 19.21 seconds
Explanation:
here we know that torque = I×α
α= angular acceleration
I = moment of inertia of hollow disc = m×
given that m=4.37kg
k=0.0710m
torque=1.2Nm


from the above equation we can calculate the angular acceleration of the hollow disc .
since 

from this above equation 
no of revolutions =
= 1,601.1943.
Now to calculate time we know that time = 
so upon calculating we will be getting t=19.21 seconds