What do we call a projectile that continually "falls" around Earth?

A soccer player kicks a rock horizontally off a 37 m high cliff into a pool of water. If the player hears the sound of the splas

Alchen [17]

<h2>Answer:</h2>

(a). 16.741 m/s

(b). 15.75 m/s

<h2>Explanation:</h2>

In the question,

Height of the cliff, h = 37 m

Time taken to reach the sound to us = 2.92 s

Speed of the sound in air at room temperature = 343 m/s

Now,

Let us say the speed of the ball = u m/s

So,

Time taken by the ball to reach at the bottom, t is given by,

$t=\sqrt{\frac{2h}{g}}\\t=\sqrt{\frac{2\times 37}{9.8}}\\t=2.747\,s$

So,

Splash is heard after = 2.92 s

So,

Time taken by sound to travel the shortest distance along the hypotenuse of the triangle thus formed is,

t = 2.92 - 2.747

t = 0.172 s

Now,

Distance traveled by sound is given by,

$Distance=343\times 0.172\\Distance=59.02\,m$

So,

In the triangle using the Pythagoras Theorem,

Horizontal distance traveled is,

$D=\sqrt{59.02^{2}-37^{2}}\\D=45.99\,m$

So,

Speed of throwing of ball is given by,

$Distance=Speed\times Time\\45.99=u\times 2.747\\u=16.741\,m/s$

Therefore, the speed of the ball = 16.741 m/s.

(b).

If,

Speed of sound = 331 m/s

So,

Distance traveled by sound is,

$Distance=331\times 0.172\\Distance=56.932\,m$

So,

Distance traveled in the horizontal by ball is,

$Distance=\sqrt{56.932^{2}-37^{2}}\\Distance=43.269\,m$

So,

Speed of the ball thrown is given by,

$Speed=\frac{Distance}{Time}\\Speed=\frac{43.269}{2.747}\\Speed=15.75\,m/s$

Therefore, the speed of the ball = 15.75 m/s.

8 0

3 years ago

Which of the following is not true about the Law of Conservation of Energy?

SVEN [57.7K]

By definition, the law of conservation of energy states that:

Ei = Ef

Where,

Ei: initial energy

Ef: final energy

Therefore, no matter the type of energy, always the final energy is equal to the final energy.

Energy can be transformed into another type of energy. For example, the potential energy can be transformed into kinetic energy.

Also, energy is not created, nor destroyed.

Answer:

The following is not true about the Law of Conservation of Energy:

A. It states that the total energy in the universe keeps increasing.

8 0

3 years ago

Read 2 more answers

It takes 200 N to move a box 10 meters in 8 seconds. How much power is

svetoff [14.1K]

Answer:

A

Explanation:

The equation of power is defined as Power = Workdone/Time Taken

And workdone = Force x Distance so using these equations we get they workdone is, 200x 10 = 2000Nm.

Dividing workdone with time will yield power, 2000 ÷ 8 = 250 Nm/s = 250W.

8 0

4 years ago

A lightbulb is rated by the power that it dissipates when connected to a given voltage. For a lightbulb connected to 120 V house

Igoryamba

Answer:

Increases, increases

Explanation:

The current is directly proportional to the voltage and inversely proportional to the resistance. The implication of this is that, whenever the voltage is increased, the current increases simultaneously. On the other hand, if the resistance is increased, the current will decrease accordingly and vice versa.

Recall that power is given by P= V^2/R where;

P= power, V= voltage and R= resistance

We can see that power and resistance are inversely related hence decreasing the resistance increases the power output of the lightbulb.

8 0

3 years ago

A material will float on the surface of a liquid if the material has a density less than that of the liquid. given that the dens

Arisa [49]

We will first convert lb to grams and in³ to milliliters.
350 lb : 2.205 = 158.75733 kg = 158,757.33 grams
1.3 · 10^4 in³ = 13,000 in³ = 13,000 · 0.016387064 = 213.031 liters
213.031 liters · 1,000 = 213,031 milliliters
Density = m / V = 158,753.33 g / 213,031 ml = 0.7452 g/ ml
Answer: A block of material will float.

6 0

3 years ago