suppose that a block is pulled 16 meters across a floor. what amount of work is done if the force used to drag the block is 22n

You yell into a canyon. You hear the echo in 3 seconds. How long did the sound of your voice travel before bouncing off a cliff?

Lilit [14]

Answer:

The sound travelled 516 meters before bouncing off a cliff.

Explanation:

The sound is an example of mechanical wave, which means that it needs a medium to propagate itself at constant speed. The time needed to hear the echo is equal to twice the height of the canyon divided by the velocity of sound. In addition, the speed of sound through the air at a temperature of 20 ºC is approximately 344 meters per second. Then, the height of the canyon can be derived from the following kinematic formula:

$2\cdot h = v\cdot t$ (1)

Where:

$h$ - Height, measured in meters.

$v$ - Velocity of sound, measured in meters per second.

$t$ - Time, measured in seconds.

If we know that $v = 344\,\frac{m}{s}$ and $t = 3\,s$ , then the height of the canyon is:

$h = \frac{v\cdot t}{2}$

$h = \frac{\left(344\,\frac{m}{s} \right)\cdot (3\,s)}{2}$

$h = 516\,m$

The sound travelled 516 meters before bouncing off a cliff.

7 0

2 years ago

A 570 kg elevator accelerates downwards at 1.5 m/s2 for the first 13 m of its motion.

jeka94

Mass of the elevator (m) = 570 Kg
Acceleration = 1.5 m/s^2
Distance (s) = 13 m
Let the force be F.
We know, F = ma,
Therefore, F = (570 × 1.5) N = 855 N
Angle between distance and force (θ) = 0°
We know, work done = F s Cos θ
Therefore, work done by the cable during this part
= (855 × 13 × Cos 0°) J
= (855 × 13 × 1) J
= 11115 J

<u>Answer</u><u>:</u>

Hope you could get an idea from here.

Doubt clarification - use comment section.

6 0

2 years ago

An electron moving in the direction of the +x-axis enters a magnetic field. If the electron experiences a magnetic deflection in

Vaselesa [24]

Answer:

<h2>As per right hand rule the force direction magnetic field is along - z axis</h2>

Explanation:

As we know that the force on the moving charge due to magnetic field is given as

$\vec F = q(\vec v \times \vec B)$

here we know that

$\vec v = v\hat i$

$q = - e$

$\vec F = F (-\hat j)$

so we will have

$F(-\hat j) = (-e)(v (\hat i) \times \vec B)$

so direction of magnetic field must be along -Z Axis

5 0

2 years ago

If the law of conversation of momentum is true,then how does the total momentum before a collision compare to the total momentum

Oxana [17]

<h2>Answer:The total momentum before collision is equal to the total momentum after collision.</h2>

Explanation:

Conservation of momentum states that whenever no external force is acting on a system,the total momentum is constant.

When we consider collisions,take the system as the two bodies that are colliding.

There are no external forces acting on the system.The forces that one body exerts on other come under internal forces.

So,momentum can be conserved in this case.

So,the total momentum before collision is equal to the total momentum after collision.

4 0

3 years ago

The trap-jaw ant can snap its mandibles shut in as little as 1.3 10-4 s. In order to shut, both mandibles rotate through a 90° a

arsen [322]

Answer

given,

Time,t = 1.3 x 10⁻⁴ s

angle of rotation = 90° = $\dfrac{\pi}{2}\ rad$

Average angular velocity of the mandible

$\omega =\dfrac{\Delta \theta}{\Delta t}$

$\omega =\dfrac{\dfrac{\pi}{2}}{1.3\times 10^{-4}}$

ω = 1.21 x 10⁴ rad/s

average angular velocity is equal to 1.21 x 10⁴ rad/s

if the time given is = 2.20 x 10⁻⁴ s

$\omega =\dfrac{\Delta \theta}{\Delta t}$

$\omega =\dfrac{\dfrac{\pi}{2}}{2.20\times 10^{-4}}$

ω = 7.14 x 10³ rad/s

average angular velocity is equal to 7.14 x 10³ rad/s

5 0

3 years ago