the third once because if you multiply them you get 2800 and 14 days is the same as 2 weeks
Answer:
(a) ω = 1.57 rad/s
(b) ac = 4.92 m/s²
(c) μs = 0.5
Explanation:
(a)
The angular speed of the merry go-round can be found as follows:
ω = 2πf
where,
ω = angular speed = ?
f = frequency = 0.25 rev/s
Therefore,
ω = (2π)(0.25 rev/s)
<u>ω = 1.57 rad/s
</u>
(b)
The centripetal acceleration can be found as:
ac = v²/R
but,
v = Rω
Therefore,
ac = (Rω)²/R
ac = Rω²
therefore,
ac = (2 m)(1.57 rad/s)²
<u>ac = 4.92 m/s²
</u>
(c)
In order to avoid slipping the centripetal force must not exceed the frictional force between shoes and floor:
Centripetal Force = Frictional Force
m*ac = μs*R = μs*W
m*ac = μs*mg
ac = μs*g
μs = ac/g
μs = (4.92 m/s²)/(9.8 m/s²)
<u>μs = 0.5</u>
The rate of energy absorption from the outdoor air is 4400 KJ/h
<u>Explanation:</u>
Coefficient of performance (COP), is an expression of the efficiency of a heat pump. When calculating the COP for a heat pump, the heat output from the condenser (Q) is compared to the power supplied to the compressor (W).
The coefficient of performance,
We replace the value in the equation with given data,
By making a conversion, we get
The energy balance,
Now, replace the values in the equation, we get
Answer: 2933 kg
Explanation:
Given
From the law of conservation of linear momentum, we know that
m(i)v(i) = m(f)v(f), where there is no external force acting on the system
m(i) = initial mass of the freight car system
m(f) = maximum mass of the freight car system
v(i) = initial linear velocity of the system
v(f) = final linear velocity of the system
2000 * 4.4 = m(f) * 3
3m(f) = 8800
m(f) = 8800 / 3
m(f) = 2933.3 kg
Therefore the maximum mass of grain that it can accept is 2933 kg