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
tresset_1 [31]
3 years ago
14

A model rocket is launched straight upward with an initial speed of 57.0 m/s. It accelerates with a constant upward acceleration

of 3.00 m/s2 until its engines stop at an altitude of 140 m. (a) What can you say about the motion of the rocket after its engines stop? This answer has not been graded yet. (b) What is the maximum height reached by the rocket? m (c) How long after liftoff does the rocket reach its maximum height? s (d) How long is the rocket in the air? s
Physics
1 answer:
Julli [10]3 years ago
4 0

Answer:

(a) The motion of rocket is in upward direction and reaches to maximum height then the rocket starts falling freely.

(b) The maximum height attained by the rocket from the ground is 348.65 m

(c) The time taken by the rocket to maximum height after lift off is 8.85 s.

(d) The total time taken by the rocket in air is 17.3 second.

Explanation:

u = 57 m/s, a = 3 m/s^2, h = 140 m

let the rocket attains a velocity v after covering 140 m and it takes t time to reach upto 140 m.

Use III equation of motion

V^2 = u^2 + 2a h

v^2 = 57^2 + 2 x 3 x 140

v = 63.95 m/s

Now use I equation of motion

v = u + at

t = (63.95 - 57) / 3 = 2.32 s

(a) The motion of rocket is in upward direction and reaches to maximum height then the rocket starts falling freely.

(b) Let H be the maximum height reached by the rocket after the engine stops.

Use III equation of motion

v^2 = u^2 + 2aH

here, v = 0, u = 63.95 m/s, a = - 9.8 m/s^2

0 = 63.95^2 - 2 x 9.8 x H

H = 208.65 m

The maximum height attained by the rocket from the ground is h + H = 140 + 208.65 = 348.65 m

(c) Let t' be the time in which rocket reaches to maximum height after engine is stopped.

Use I equation of motion

v = u + a t'

0 = 63.95 - 9.8 x t'

t' = 6.53 s

The time taken by the rocket to maximum height after lift off is t + t' = 2.32 + 6.53 = 8.85 s.

(d) let t'' be the time taken by the rocket to fall freely

Use II equation of motion

H' = ut'' + 1/2 gt''^2

Here, H' = 348.65 m, u = 0

348.65 = 0 + 0.5 x 9.8 x t''^2

t''^ = 8.44 s

The total time taken by the rocket in air is t + t' + t'' = 2.32 + 6.53 + 8.44 = 17.3 second.

You might be interested in
think about something that has happened to you physically—a fall, a jump, an accident, or something you may have done hundreds o
timurjin [86]

My best hobby is driving. Driving has something to do with Newton's first law of motion, which states that an object will continue to be in its state of rest or in uniform motion in a straight line unless it is acted upon by an external force. This law means that an object will continue to be in motion in the same direction unless it is acted upon by a force. Newton's first law of motion is also called the law of inertia.

I usually experience the law of inertia when I am driving my car.

Every morning, for me to move the car from its state of rest to a state of uniform motion, I have to switch on the ignition, which represent an unbalanced force that move the car out of its states of rest. When I am driving, the car continue in motion and in the same direction, unless I apply the brake. The application of the brake is an example of applying an unbalanced force to stop a body in motion.

5 0
3 years ago
A lightweight string is wrapped several times around the rim of a small hoop. If the free end of the string is held in place and
MariettaO [177]

Answer:

Explanation:

Let T be the tension

For linear motion of hoop downwards

mg -T = ma , m is mass of the hoop . a is linear acceleration of CG of hoop .

For rotational motion of hoop

Torque by tension

T x R ,      R is radius of hoop.

Angular acceleration be α,

Linear acceleration a = α R

So TR = I  α

= I  a / R

a = TR² / I

Putting this value in earlier relation

mg -T = m TR² / I

mg = T ( 1 + m R² / I )

T = mg / ( 1 + m R² / I )

mg / ( 1 + R² / k² )

Tension is less than mg or weight because denominator of the expression is more than 1.

5 0
3 years ago
Which of the following describes how the mechanical advantage of a simple machine affects the amount of force needed for work? A
Simora [160]

Answer:

The answer is a

Explanation:

5 0
3 years ago
How could we expect a white paper to appear when viewed in a red light?
Xelga [282]
The accurate answer is:
You could expect a white paper to have a red tone when viewed in a red light. This is the case because of the neutrality of the white paper.
4 0
3 years ago
Guys help...A spring that obeys Hooke's law, with a spring constant k1, is cut into N identical springs, each with a spring cons
Tems11 [23]

Answer:

K2 = N*K1

Explanation:

The force you apply to each section is the same you apply to the whole spring, but the extension of each section is dX/N (if dX is the extension of the entire spring)

4 0
3 years ago
Other questions:
  • A star's transverse velocity depends on which two factors?
    6·1 answer
  • I need C,D,E,F,H please ​
    12·1 answer
  • A 65-cm segment of conducting wire carries a current of 0.35
    12·2 answers
  • An ideal spring hangs from the ceiling. A 1.55 kg1.55 kg mass is hung from the spring, stretching the spring a distance ????=0.0
    7·1 answer
  • Are graded receptor potentials always depolarizing? Do graded receptor potentials always make it easier to induce action potenti
    7·1 answer
  • What are three important details to know about an object's motion? Position, speed, density Speed, acceleration, position Positi
    11·2 answers
  • heather and matthew walk with an average velocity of 98 m/s eastward. If it takes them 34 min ro walk to the store, what is thei
    9·1 answer
  • A bullet is fired vertically upward a velocity of 80m/s to what height will the bullet rise above the point of projection​
    6·1 answer
  • What does a star turn hydrogen into?
    13·2 answers
  • Please help with this one
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!