Answer:
24.57 revolutions
Explanation:
(a) If they do not slip on the pavement, then the angular acceleration is

(b) We can use the following equation of motion to find out the angle traveled by the wheel before coming to rest:

where v = 0 m/s is the final angular velocity of the wheel when it stops,
= 95rad/s is the initial angular velocity of the wheel,
is the deceleration of the wheel, and
is the angle swept in rad, which we care looking for:



As each revolution equals to 2π, the total revolution it makes before stop is
154.375 / 2π = 24.57 revolutions
Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is,
, were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as
, and the mass of the first and second coals as
and
respectively
We start with the transition between parts A and B, so we have:

Which means

And since we want the mass of the first coal thrown (
) we do:



Substituting values we obtain

For the transition between parts B and C, we can write:

Which means

Since we want the new final speed of the car (
) we do:

Substituting values we obtain

Answer:
A.
Explanation:
We are given that

Density,
Tension,T=38 N
We have to find the density of liquid.


Volume,V=




Option A is true.
false. all obejects in motion have friction
D, I hope this is correct!