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3 years ago

Which statements describe a situation in which work is being done? Check all that apply.

Physics

2 answers:

slava [35]3 years ago

5 0

The work is being done in following cases:

A mover carries a box up a flight of stairs.

A mover carries a box across a room.

Wind blows a pool chair across the yard.

A weightlifter lifts a barbell off the ground.

These are the only cases in which work is being done. The Formula of Work is:

Work= Force applied x Distance moved.

In all of these cases force is being applied and the object on which the force is being applied move in a horizontal or Vertical direction. Thus Work is done !

DanielleElmas [232]3 years ago

5 0

Answer:

A. A box is carried up a flight of stairs by a mover.

D. Wind blows a pool chair across the yard.

E. A weightlifter lifts a barbell off the ground.

Explanation:

You might be interested in

Why do radio waves have the lowest frequency of all the waves on the electromagnetic spectrum?

lara [203]

Explanation:

Electromagnetic waves are the waves which are created as the result of the electrical waves which are perpendicular to each other and also perpendicular to the direction of propagation.

Electromagnetic spectrum is range of the frequencies and their respective wavelengths of the various type of the electromagnetic radiation.

In order of the increasing frequency and the photon energy and the decreasing wavelength the spectrum are:

radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays.

The energy of the radio waves photons is the lowest of all the other waves in the electromagnetic spectrum.

Also, $E={h\times \nu}$

Where,

h is Plank's constant having value $6.626\times 10^{-34}\ Js$

Thus, energy is directly proportional to the frequency. The radio waves have the lowest frequency.

8 0

3 years ago

During a softball game, a player running from second base to third base reaches a speed

andrey2020 [161]

Answer: I would say it would be 3.9

but i believe there is something missing shorty.

4 0

2 years ago

Mechanical waves propagate or move through a medium because

lys-0071 [83]

The answer to that would be that

they require so its mandatory for mechanical waves to travel through a medium

8 0

3 years ago

If you traveled 90 km in 0.50 hours, what <br><br> was your average speed

Alinara [238K]

Average speed = distance / time

Average speed = 90 km / 0.5 hrs

Average speed = 180 km per hour

8 0

3 years ago

Se golpea una pelota de golf de manera que su velocidad inicial forma un ángulo de 45° con la horizontal. La pelota alcanza el s

nordsb [41]

Answer:

42m/s

6.06s

Explanation:

To find the initial velocity and time in which the ball is fling over the ground you use the following formulas:

$x_{max}=\frac{v_o^2sin(2\theta)}{g}\\\\x_{max}=vt_{max}$

θ: angle = 45°

vo: initial velocity

g: gravitational constant = 9.8m/s^2

x_max: max distance = 180 m

t_max: max time

by replacing the values of the parameters and do vo the subject of the first formula you obtain:

$v_o=\sqrt{\frac{gx_{max}}{sin(2\theta)}}\\\\v_o=\sqrt{\frac{(9.8m/s^2)(180m)}{sin(2(45\°))}}=42\frac{m}{s}$

with this value of vo you calculate the max time:

$t_{max}=\frac{x_{max}}{v}=\frac{x_{max}}{v_ocos(45\°)}\\\\t_{max}=\frac{180m}{(42m/s)cos(45\°)}=6.06s$

hence, the initial velocity of the ball is 42m/s and the time in which the ball is in the air is 6.06s

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TRANSLATION:

Para encontrar la velocidad inicial y el tiempo en el que la pelota está volando sobre el suelo, use las siguientes fórmulas:

θ: ángulo = 45 °

vo: velocidad inicial

g: constante gravitacional = 9.8m / s ^ 2

x_max: distancia máxima = 180 m

t_max: tiempo máximo

reemplazando los valores de los parámetros y haciendo el tema de la primera fórmula que obtiene:

con este valor de vo usted calcula el tiempo máximo:

por lo tanto, la velocidad inicial de la pelota es de 42 m / sy el tiempo en que la pelota está en el aire es de 6.06 s

4 0

2 years ago