A car driver takes a total of two hours to make a journey of 75 km. She has a coffee

Which of the following is true about light waves and sound waves? A. Sound waves can move at different speeds, but light waves a

vivado [14]

Answer:

C

Explanation:

Sound waves speed up noticeably when moving through a solid or liquid, because all it is is just particles colliding; and particles are way closer together with those states of matter.

The speed of light can change when moving through different substances, but this is dependent on complicated factors such as frequency, polarization, intensity, et. cetera

The important part is that it does change speed, so your answer is C.

Hope this helps!

3 0

3 years ago

A 120 kg box is on the verge of slipping down an inclined plane with an angle of inclination of 47º. What is the coefficient of

Alex_Xolod [135]

Given :

A 120 kg box is on the verge of slipping down an inclined plane with an angle of inclination of 47º.

To Find :

The coefficient of static friction between the box and the plane.

Solution :

Vertical component of force :

$mg\ sin\ \theta = 120\times 10 \times sin\ 47^\circ{}=877.62 \ N$

Horizontal component of force(Normal reaction) :

$mg\ cos\ \theta = 120\times 10 \times cos\ 47^\circ{}=818.40 \ N$

Since, box is on the verge of slipping :

$mg\ sin\ \theta= \mu(mg \ cos\ \theta)\\\\\mu = tan \ \theta\\\\\mu = tan\ 47^o\\\\\mu = 1.07$

Therefore, the coefficient of static friction between the box and the plane is 1.07.

Hence, this is the required solution.

7 0

3 years ago

William WangHomework #33 Regents Review (3)0989Assignment Mode : Open (Time On Task) 9 of 25 ListenDuring a collision, an 84-kil

Lemur [1.5K]

Answer:

$1.7\cdot 10^3 N$

Explanation:

The impulse theorem states that the product between the force and the time interval of the collision is equal to the change in momentum:

$F \Delta t = m \Delta v$

where

F is the force

$\Delta t$ is the time interval

m is the mass

$\Delta v$ is the change in velocity

Here we have

m = 84 kg

$\Delta t = 1.2 s$

$\Delta v = 24 m/s$

So we can solve the equation to find the force:

$F= \frac{m \Delta v}{\Delta t }=\frac{(84 kg)(24 m/s)}{1.2 s}=1680 N \sim 1.7\cdot 10^3 N$

4 0

3 years ago

You and a friend are studying late at night. There are three 110 W light bulbs and a radio with an internal resistance of 56.0 Ω

Sliva [168]

Answer:

The total electrical power we are using is: 1316 W.

Explanation:

Using the ohm´s law $V=I*R$ and the formula for calculate the electrical power, we can find the total electrical power that we are using. First we need to find each electrical power that is using every single component, so the radio power is: $I=\frac{V}{R}=\frac{110 (v)}{56(ohms)}=1.96(A)$ , so the radio power is: $P=I*V=1.96(A)*110(v)=216(W)$ , then we find the pop-corn machine power as: $P=I*V=7(A)*110(v)=770(W)$ and finally there are three light bulbs of 110(W) so: P=3*110(W)=330(W) and the total electrical power is the adding up every single power so that: P=330(W)+770(W)+216(W)=1316(W).

8 0

3 years ago

If a scale of the solar system was built where 1 mm equaled 1 mile, could the model be practically built in a city?

Y_Kistochka [10]

No, it couldn't be.
On that scale, Neptune would be almost 1,740 MILES from the sun.
ON THAT SCALE !

7 0

3 years ago

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