In thermodynamics, work is typically done by

1. Which of the following is NOT a vector quantity? (a) Displacement. (b) Energy. (c) Force. (d) Momentum. (e) Velocity.

dem82 [27]

Answer:

B. energy

Explanation:

A vector has direction.

Energy does not have a direction.

5 0

3 years ago

A quarterback throws a football with an angle of elevation 55Â° and speed 60 ft/s. Find the horizontal and vertical components o

EastWind [94]

Answer:

The horizontal component of the velocity vector is;

vh = 34.4 ft/s

The vertical component of the velocity vector is;

vy = 49.1 ft/s

Explanation:

Given;

Velocity of football v = 60 ft/s

Angle of elevation ∅ = 55°

The horizontal component of the velocity vector is;

vh = vcos∅

Substituting the values;

vh = 60cos55°

vh = 34.41458618106 ft/s

vh = 34.4 ft/s

The vertical component of the velocity vector is;

vy = vsin∅

Substituting the values;

vy = 60sin55°

vy = 49.14912265733 ft/s

vy = 49.1 ft/s

7 0

3 years ago

__________ is a type of molding in which thermoplastics are heated above melting temperature and, using an extruder, are forced

Ymorist [56]

Answer: The correct and is

D. Extrusion

Explanation:

What is extrusion?

Extrusion is a manufacturing process used to make basically pipes and hoses.

The pvc granules are melt into a liquid which is forced through a die, forming a long 'tube like' shape. The shape of the die determines the shape of the tube.

The extrusion is then cooled and forms a solid shape

Extrusion moulding is used to create products with a consistent cross-section.

4 0

3 years ago

What is the average power output pf a weight lifter who can lift 250 kg 2.0 m in 2.0 s

liq [111]

Answer:

Power = 2.45Kw or 2450 Watts.

Explanation:

<u>Given the following data;</u>

Mass, m = 250kg

Height, h = 2m

Time, t = 2secs

We know that acceleration due to gravity, g is equal to 9.8m/s²

Power can be defined as the energy required to do work per unit time.

Mathematically, it is given by the formula;

$Power = \frac {Energy}{time}$

But Energy = mgh

Substituting into the equation, we have

$Power = \frac {mgh}{time}$

$Power = \frac {250*9.8*2}{2}$

$Power = \frac {4900}{2}$

Power = 2450 Watts

To convert to kilowatt (Kw), we would divide by 1000

Power = 2450/1000

Power = 2.45Kw.

Therefore, the average power output of the weightlifter is 2.45 Kilowatts.

8 0

3 years ago

Se deja resbalar por un plano inclinado de 30° un cuerpo de 15kg. Calcular la aceleración con la que desciende suponiendo que no

kupik [55]

Answer:

$4.9 m/s^2$

Explanation:

In order to find the acceleration of the block, we have to find the net force acting on it along the direction parallel to the incline.

However, there is only one force acting on the block along this direction: it is the component of the weight parallel to the plane, given by

$mg sin \theta$

where

m = 15 kg is the mass of the block

$g=9.8 m/s^2$ is the acceleration of gravity

$\theta=30^{\circ}$ is the angle of the incline

According to Newton's second law, the net force is proportional to the acceleration, a:

$F=ma$

So we can write:

$ma = mg sin \theta$

And so, the acceleration is:

$a=g sin \theta = (9.8)(sin 30^{\circ})=4.9 m/s^2$

7 0

3 years ago