All categories

4 years ago

3. In which activity is no work done?

Physics

1 answer:

Firlakuza [10]4 years ago

6 0

Answer:

Sleeping, since your brain is working, but your physical body is not moving at all or moving rarely, therefore there is no work done in the activity of sleeping.

Explanation:

You might be interested in

Two identical speakers are emitting a constant tone that has a wavelength of 0.50 m. Speaker A is located to the left of speaker

Marianna [84]

Answer:

a) and c).

Explanation:

For a complete destructive interference occur, it must be met the following condition relating the wavelength, and the difference in the paths taken by the sound emitted by the sources until arriving to the listening point:

d = |dA- dB| = (2n-1)*(λ/2)

For n= 1, d = λ/2 = 0.25 m, it doesn't meet any of the cases.

For n=2, d= 3*(λ/2) = 0.75 m

In the case a) we have dA = 2.15 m and dB = 3.00 m, so dB-dA = 0.75 m, which means that in the location stated by case a) a complete destructive interference would occur.

For n=3, d= 5*(λ/2) = 5*0.25 m = 1.25 m.

This is just the case c) because we have dA = 3.75 m and dB = 2.50 m, so dA-dB = 1.25 m, which means that in the location stated by case c) a complete destructive interference would occur also.

The remaining cases don't meet the condition stated above, so the statements found to be true are a) and c),

5 0

3 years ago

The sun's rays have a greater effect on land temperature than they have on water temperature. This can be explained partly by wh

____ [38]

Answer:

The answer is choice (3)

Explanation: Land materials do require more energy than water to raise their temperature by one degree, hence why water gets heated a lot easier than something like wood.

5 0

3 years ago

Un automovil parte del reposo y acelera uniformemente hasta alcanzar una rapidez de 0,255km/h en un tiempo de 3/4 Minutos determ

Elden [556K]

Answer:

a = 1.5*10^-3 m/s^2

x = 0.033m = 3.3cm

Explanation:

To calculate the acceleration and the distance traveled by the car you use the following formulas:

$v=v_o+at$ (1)

$x=v_ot+\frac{1}{2}at^2$ (2)

v: final velocity = 0,255 km/h

vo: initial velocity = 0 m/s

t: time = 3/4 min

a: acceleration = ?

x: distance

In order to use the equations (1) and (2) you first convert the units of the final velocity to m/s, and the time to seconds.

$v=0,255\frac{km}{h}*\frac{1000m}{1km}*\frac{1h}{3600s}\\\\v=0.07m/s\\\\t=\frac{3}{4}min*\frac{60s}{1min}=45s$

Next, you solve the equation (1) for the acceleration a:

$a=\frac{v}{t}=\frac{0.07m/s}{45s}=1.5*10^{-3}\frac{m}{s^2}$

With this value of a you can calculate the distance traveled by the car, by using the equation (2):

$x=\frac{1}{2}(1.5*10^{-3}m/s^2)(45s)^2=0.033m=3.3cm$

hence, the acceleration of the car is 1.5*10^-3 m/s^2 and the distance traveled in 3/4 min is 0.033m

5 0

3 years ago

Two forces act on a 6.00- kg object. One of the forces is

Stella [2.4K]

Answer:

Fx = 22N

Explanation:

There are 2 possible scenarios for this problem:

1.- The 10N force is in the same direction of the acceleration. In this case the other force would be:

$F1 - Fx = m*a$ where F1 = 10N, m=6kg, a = 2m/s2

$Fx = F1 - m*a = -2N$ The negative result tells us that this is not possible.

2.- The 10N force is in the opposite direction of the acceleration. In this case the other force would be:

$Fx - F1 = m*a$ $Fx = m*a + F1 = 22N$

3 0

4 years ago

A bullet with mass 0.04000 kg, traveling at a speed of 310.0 m/s, strikes a stationary block of wood having mass 6.960 kg. The b

ch4aika [34]

Answer:

1.77 m/s

Explanation:

From the law of conservation of momentum,

Total momentum before collision = Total momentum after collision

mu+m'u' = V(m+m')............................ Equation 1

Where m = mass of the bullet, m' = mass of the block, u = initial velocity of the bullet, u' = initial velocity of the block, V = Velocity of the bullet-wood combination immediately after collision

make V the subject of the equation

V = (mu+m'u')/(m+m').................. Equation 2

Given: m = 0.04 kg, m' = 6.96 kg, u = 310 m/s, u' = 0 m/s (stationary)

Substitute into equation 2

V = (0.04×310+6.96×0)/(0.04+6.96)

V = 12.4/7

V = 1.77 m/s

Hence the speed, in m/s, of the bullet-plus-wood combination immediately after the collision is 1.77 m/s

6 0

4 years ago