Of the two forms of friction you studied,_____ friction is the one that must be overcome in order to start something moving.

For a particular reaction, the change in enthalpy is 51kJmole and the activation energy is 109kJmole. Which of the following cou

Ronch [10]

Answer

given,

change in enthalpy = 51 kJ/mole

change in activation energy = 109 kJ/mole

when a reaction is catalysed change in enthalpy between the product and the reactant does not change it remain constant.

where as activation energy of the product and the reactant decreases.

example:

ΔH = 51 kJ/mole

E_a= 83 kJ/mole

here activation energy decrease whereas change in enthalpy remains same.

5 0

2 years ago

A pipe is horizontal and carries oil that has a viscosity of 0.14 Pa s. The volume flow rate of the oil is 5.3 × 10-5 m3/s. The

Liula [17]

Answer:

Explanation:

Given

$\mu =0.14 Pa.s$

Volume Flow rate $Q=5.3\times 10^{-5} m^3/s$

Length $L=37 m$

radius $r=0.58 cm$

$D=1.16 cm$

According to Hagen-Poiseuille Equation

difference in Pressure is given

$\Delta P=\frac{128\mu L\cdot Q}{\pi D^4}$

$P_{in}-P_{out}=\frac{128\mu L\cdot Q}{\pi D^4}$

$P_{in}=P_{out}+\frac{128\mu L\cdot Q}{\pi D^4}$

$P_{in}=1.01325\times 10^5+\frac{128\times 0.14\times 37\times 5.3\times 10^{-5}}{\pi\cdot 1.16^4\times 10^{-8}}$

$P_{in}=1.01325\times 10^5+6.17\times 10^5$

$P_{in}=7.19\times 10^5$

3 0

2 years ago

Harry and ron set up this experiment with a glider, whose mass they have measured to be 565 g, and seven washers hanging from th

svetlana [45]

Let's call $m=565~g=0.565~kg$ the mass of the glider and $m_w=7\cdot12~g =84~g=0.084~kg$ the total mass of the seven washers hanging from the string.
The net force on the system is given by the weight of the hanging washers:
$F_{net} = m_w g$
For Newton's second law, this net force is equal to the product between the total mass of the system (which is $m+m_w$ ) and the acceleration a:
$F_{net}=(m+m_w)a$
So, if we equalize the two equations, we get
$m_w g = (m+m_w)a$
and from this we can find the acceleration:
$a= \frac{m_w g}{(m+m_w)} = \frac{0.084~kg \cdot 9.81~m/s^2}{(0.565~kg+0.084~kg)}=1.27~m/s^2$

5 0

2 years ago

A crane lifts an air conditioner to the top of a building. If the building is 12 m high, and the air conditioner has a mass of 2

Pepsi [2]

Work needed = 23,520 J

<h3> Further explanation </h3>

Given

height = 12 m

mass = 200 kg

Required

work needed by the crane

Solution