Ask question

Ask question

All categories

2 years ago

9

A tennis ball is tossed upwards into the air with an initial velocity of +5m/s, how much time does it take for the tennis ball t

o reach this point?

1 answer:

Sever21 [200]2 years ago

3 0

HOPE THIS HELPS YOU!!!!!

You might be interested in

If a student weighs 100 pounds on Earth, how much more or less would she weigh on Pluto than Mars?

Sever21 [200]

Answer:

c because that's the answer

4 0

2 years ago

*NEED ANSWER QUICKLY!*

umka21 [38]

You would have to put the number together

8 0

2 years ago

Tell me any 5 importance of medicinal plants

s344n2d4d5 [400]

Answer:

Aloe, Tulsi, Neem, Turmeric, and Ginger are medicinal plants that can help with a variety of diseases. Ginger, green tea, walnuts, aloe, pepper, and turmeric are just a few of these plants. Some plants and their derivatives are key sources of active compounds used in aspirin and toothpaste, among other things.

Explanation:

Plant name: Uses:

1. Marshmallow: //// Relief from aching muscles and pain in muscle, Heals insect bite. ////

2.California poppy //// Relieves tension, Removes nervous system

3. Tulsi //// Cures sore throat, Cures fever and asthma

4. Neem //// Cures skin diseases, Cures diabetics

5. Aloevera //// Heals burns, Relieves constipation

(Hope this helps can I pls have brainlist (crown)☺️)

3 0

3 years ago

A concert loudspeaker suspended high off the ground emits 34 W of sound power. A small microphone with a 1.0 cm2 area is 44 m fr

rjkz [21]

Answer:

<u>Part A</u>

I = 1.4 mW/m²

<u>Part B</u>

β = 91.46 dB

Explanation:

<u>Part A</u>

Sound intensity is the power per unit area of sound waves in a direction perpendicular to that area. Sound intensity is also called acoustic intensity.

For a spherical sound wave, the sound intensity is given by;

$I = \frac{P}{A}$

$I = \frac{P}{4\pi r^{2}}$

Where;

P is the source of power in watts (W)

I is the intensity of the sound in watt per square meter (W/m2)

r is the distance r away

Given:

P = 34 W,

A = 1.0 cm²

r = 44 m

The sound intensity at the position of the microphone is calculated to be;

$I = \frac{34}{4\pi (44)^{2}}$

$I = \frac{34}{4\pi (44)^{2}}$

I = 0.0013975 W/m²

≈ I = 0.0014 W/m² = 1.4 × 10⁻³ W/m²

I = 1.4 mW/m²

The sound intensity at the position of the microphone is 1.4 mW/m².

<u>Part B</u>

Sound intensity level or acoustic intensity level is the level of the intensity of a sound relative to a reference value. It is a a logarithmic quantity. It is denoted by β and expressed in nepers, bels, or decibels.

Sound intensity level is calculated as;

β $= 10log_{10}\frac{I}{I_{0}}$ dB

Where,

β is the Sound intensity level in decibels (dB)

I is the sound intensity;

I₀ is the reference sound intensity;

By pluging-in, I₀ is 1.0 × 10⁻¹² W/m²

∴ β $= 10log_{10}\frac{1.4 * 10^{-3} W/m^{2}}{1.0 * 10^{-12} W/m^{2}}$

β $= 10log_{10} (1.4 * 10^{9})$

β = 91.46 dB

The sound intensity level at the position of the microphone is 91.46 dB.

4 0

3 years ago

12. A rocket, initially at rest on the ground, accelerates vertically. It accelerates uniformly until it

vodomira [7]

Answer:

We kindly invite you to read carefully the explanation and check the image attached below.

Explanation:

According to this problem, the rocket is accelerated uniformly due to thrust during 30 seconds and after that is decelerated due to gravity. The velocity as function of initial velocity, acceleration and time is:

$v_{f} = v_{o}+a\cdot (t-t_{o})$ (1)

Where:

$v_{o}$ - Initial velocity, measured in meters per second.

$v_{f}$ - Final velocity, measured in meters per second.

$a$ - Acceleration, measured in meters per square second.

$t_{o}$ - Initial time, measured in seconds.

$t$ - Final time, measured in seconds.

Now we obtain the kinematic equations for thrust and free fall stages:

Thrust ( $v_{o} = 0\,\frac{m}{s}$ , $a = 30\,\frac{m}{s^{2}}$ , $t_{o} = 0\,s$ , $0\,s\le t< 30\,s$ )

$v = 30\cdot t$ (2)

Free fall ( $v_{o} = 900\,\frac{m}{s}$ , $a = -9.807\,\frac{m}{s}$ , $t_{o} = 30\,s$ , $30\,s \le t \le 120\,s$ )

$v = 900-9.81\cdot (t-30)$ (3)

Now we created the graph speed-time, which can be seen below.

5 0

3 years ago