1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
liberstina [14]
3 years ago
6

If a ball is thrown vertically upward with a velocity of 80 ft/s, then its height after t seconds is s = 80t − 16t 2 . (a) what

is the maximum height reached by the ball? (b) what is the velocity of the ball when it is 96 ft above the ground on its way up? on its way down?
Physics
1 answer:
MAXImum [283]3 years ago
4 0
Max height occurs when v = 0.
v(t) = ds(t)/dt
v(t) = 80 - 32t
0 = 80 - 32t
t = 5/2

s(5/2) = 80(5/2) - 16(5/2)^2
s(5/2) = 100
Answer: 100 ft

96 = 80t - 16t²
t = 3, 2
(80 ± √256) / 32 using the quadratic equation.

v(2) = 16
v(3) = -16
You might be interested in
A small omnidirectional stereo speaker produces waves in all directions that have an intensity of 8.00 at a distance of 4.00 fro
slavikrds [6]

Answer:

A. We have that radius r = 4.00m intensity I = 8.00 W/m^

total power = power/ Area ( 4πr2)= 8.00 w/m^2( 4π ( 4.00 m)2=1607.68 W

b) I = total power/ 4πr2= 8.00 W/m2 ( 4.00 m/ 9.5 m)2= 1.418 W/m2

c) E = total power x time= 1607 . 68 W x 1s= 1607.68 J

5 0
3 years ago
A proton is moving in a circular orbit of radius 12 cm in a uniform 0.31-T magnetic field perpendicular to the velocity of the p
PIT_PIT [208]

Answer:

Explanation:

A proton of charge

q=+1.609×10^-19C

Orbit a radius of 12cm

r=0.12m

Magnetic Field of 0.31T

Angle between velocity and field is 90°

a. Because the magnetic force F supplies the centripetal force Fc.

The magnitude of the magnetic force F on a charge q moving at a speed v in a magnetic field of strength B is given by

F = qvB sin θ

And the centripetal force is given as

Fc=mv²/r

Where m is mass of proton

m=1.673×10^-27kg

Then, F=Fc

qvB sin θ=mv²/r

qBSin90=mv/r

rqB=mv

Then, v=rqB/m

v=0.12×1.609×10^-19×0.31/1.673×10^-23

v=3577692.78m/s

v=3.58×10^6m/s

b. Since,

F=qVBSin90

F=1.609×10^-19×3.58×10^6×0.31

F=1.785×10^-13 N.

6 0
3 years ago
a ultrasonic wave at 8x10^4 Hz is emitted into a vien where the speed of sound in blood is 1570 m/s. the wave reflects off the r
Aneli [31]

Answer: 0.392 m/s

Explanation:

The Doppler shift equation is:

f'=\frac{V+V_{o}}{V-V_{s}} f

Where:

f=8(10)^{4} Hz is the actual frequency of the sound wave

f'=8.002(10)^{4} Hz is the "observed" frequency

V=1570 m/s is the speed of sound

V_{o}=0 m/s is the velocity of the observer, which is stationary

V_{s} is the velocity of the source, which are the red blood cells

Isolating V_{s}:

V_{s}=\frac{V(f'-f)}{f'}

V_{s}=\frac{1570 m/s(8.002(10)^{4} Hz-8(10)^{4} Hz)}{8.002(10)^{4} Hz}

Finally:

V_{s}=0.392 m/s

3 0
3 years ago
For a standard production car, the highest road-tested acceleration ever reported occurred in 1993, when a Ford RS200 Evolution
Ann [662]

Answer:

a = 8.06 m/s²

Explanation:

The acceleration of this car can be found using the first equation of motion:

v_f = v_i + at\\\\a = \frac{v_f-v_i}{t}

where,

a = acceleration = ?

vf = final speed = 26.8 m/s

vi = initial speed = 0 m/s

t = time = 3.323 s

Therefore,

a = \frac{26.8\ m/s-0\ m/s}{3.323\ s}

<u>a = 8.06 m/s²</u>

3 0
2 years ago
I NEED HELP ASAP!!!
alekssr [168]

Answer:

B) 3.6x 10_6 N/C or D)2.8 x105 N/C

7 0
3 years ago
Other questions:
  • A ball is dropped from a height of 2 m. how long will it take this ball to reach the ground?
    13·1 answer
  • If a star’s radiation peaks in the ultraviolet region of the spectrum, what could you conclude?
    9·2 answers
  • When must scientific theories be changed?
    12·2 answers
  • What is true about all scientists
    6·1 answer
  • This force involves the attraction between objects with mass.
    8·2 answers
  • A heat engine is designed to do work. This is possible only if certain relationships between the heats and temperatures at the i
    14·1 answer
  • Explain why gases make better thermal insulators than solids or liquids.​
    10·2 answers
  • Help ?
    14·1 answer
  • Which is TRUE about static electricity?
    12·2 answers
  • Electrical energy is sold by the kilowatt hour How much would it cost to heat a hot tub from 15 to 43
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!