The first five questions refer to the following problem:

Calculate the mechanical advantage of a hammer, if the input force is 125 N

olganol [36]

Answer:

16

Explanation:

Mechanical advantage = force out / force in

MA = 2000 N / 125 N

MA = 16

5 0

3 years ago

The exit nozzle in a jet engine receives air at 1200 K, 150 kPa with negligible kinetic energy. The exit pressure is 80 kPa, and

nikitadnepr [17]

Complete question:

The exit nozzle in a jet engine receives air at 1200 K, 150 kPa with negligible kinetic energy. The exit pressure is 80 kPa, and the process is reversible and adiabatic. Use constant specific heat at 300 K to find the exit velocity.

Answer:

The exit velocity is 629.41 m/s

Explanation:

Given;

initial temperature, T₁ = 1200K

initial pressure, P₁ = 150 kPa

final pressure, P₂ = 80 kPa

specific heat at 300 K, Cp = 1004 J/kgK

k = 1.4

Calculate final temperature;

$T_2 = T_1(\frac{P_2}{P_1})^{\frac{k-1 }{k}$

k = 1.4

$T_2 = T_1(\frac{P_2}{P_1})^{\frac{k-1 }{k}}\\\\T_2 = 1200(\frac{80}{150})^{\frac{1.4-1 }{1.4}}\\\\T_2 = 1002.714K$

Work done is given as;

$W = \frac{1}{2} *m*(v_i^2 - v_e^2)$

inlet velocity is negligible;

$v_e = \sqrt{\frac{2W}{m} } = \sqrt{2*C_p(T_1-T_2)} \\\\v_e = \sqrt{2*1004(1200-1002.714)}\\\\v_e = \sqrt{396150.288} \\\\v_e = 629.41 \ m/s$

Therefore, the exit velocity is 629.41 m/s

6 0

3 years ago

What is the speed of a cheetah that travels 176.4 meters in 4.5 seconds?

Ugo [173]

Answer:

$\boxed{ \bold{ \boxed{ \sf{39.2 \: m/ {s} \: }}}}$

Explanation:

Given,

Distance travelled ( d ) = 176.4 meters

Time taken ( t ) = 4.5 seconds

Finding the speed of a cheetah

Speed $\sf{ = \frac{distance \: travelled}{time \: taken} }$

$\sf{ = \frac{176.4}{4.5} }$

$\sf{ = 39.2 \: m/ {s} \: }$

------------------------------------------------------------------------

Let's learn about Speed  :

Suppose a body moves 20 m in 2 seconds, either on a curved path or on a straight path. So , 10 m is the distance travelled by the body in each second which can be written as 10 m/s. This is called speed of the body. Thus, Speed is defined as the distance travelled per unit time. It is the rate of distance travelled by a body.

Mathematically,

$\boxed{ \bold{ \sf{speed = \frac{distance \: travelled}{time \: taken} }}}$

In SI system, the unit of distance is metre and time is second. Thus , the SI unit is speed is m/s.

Hope I helped!

Best regards!!

8 0

2 years ago

Differentiate between a derived quantity and a derived unit.

Inessa [10]

Explanation:

Derived quantities are quantities dependent on fundamental quantities while derived units are the units of these quantities

3 0

2 years ago

Which of the following particle is responsible for the transfer of static charge?

djverab [1.8K]

Answer:

B. Electron

Static charge is produced by electron transfer.

Explanation:

Answer A: The neutron does not possess a charge and is said to be neutral.

Answer D: Protons and neutrons never move from object to object.

Only negative charges can move freely from one object to another. The energy that comes from these charges particles is called electrical energy.

....

Hope this answer can help you.

4 0

3 years ago