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
sesenic [268]
3 years ago
8

A dynamite blast at a quarry launches a rock straight upward, and 1.7 s later it is rising at a rate of 17 m/s. Assuming air res

istance has no effect on the rock, calculate its speed (a) at launch and (b) 4.9 s after launch.
Physics
1 answer:
Shtirlitz [24]3 years ago
3 0

Answer:

(a) v_0= 34m/s

(b) v=14m/s

Explanation:

We can derive the initial speed of the rock from the equation of the speed in function of the time:

v=v_0-gt\\\\\implies v_0=v+gt

Using the given values for the speed at time t=1.7s, we get:

v_0=17m/s+(9.8m/s^{2})(1.7s)=34m/s

In words, the speed of the rock at launch is 34m/s (a).

Next, we use this to calculate the speed at t=4.9s:

v=v_0-gt\\\\v= 34m/s-(9.8m/s^{2})(4.9s)=-14m/s

This means that the speed of the rock at 4.9s after the launch is 14m/s (b), and the negative sign means that it is moving downwards.

You might be interested in
Water from a vertical pipe emerges as a 10-cm-diameter cylinder and falls straight down 7.5 m into a bucket. The water exits the
cupoosta [38]

The diameter of the column of the water as it hits the bucket is 4.04 cm

The equation of continuity occurs in the fluid system and it asserts that the inflow and the outflow of the volume rate at the inlet and at the outlet of the system are equal.

By using the kinematics equation to determine the speed of the water in the bucket and applying the equation of continuity to estimate the diameter of the column, we have the following;

Using the kinematics equation:

\mathbf{v_f ^2 = v_i^2 + 2gh}

\mathbf{v_f ^2 =(2.0)^2 + 2\times 9.8 \times 7.5}

\mathbf{v_f ^2 =151 m/s}

\mathbf{v_f  =\sqrt{151 m/s}}

\mathbf{v_f  =12.29 \ m/s}  

From the equation of continuity:

\mathbf{A_iV_i = A_fV_f}

\mathbf{\pi r^2_iV_i = \pi r^2_fV_f}

\mathbf{ r^2_iV_i =  r^2_fV_f}

\mathbf{ (\dfrac{10}{2})^2\times 2.0 =  r_f^2 \times 12.29}

\mathbf{ 50 = 12.29 \times r_f^2}

\mathbf{ r_f=  \sqrt{\dfrac{50}{12.29} }}

\mathbf{ V_f= 2.02 \ cm }

Since diameter = 2r;

∴

The diameter of the column of the water is:

= 2(2.02) cm

= 4.04 cm

Learn more about the equation of continuity here:

brainly.com/question/10822213

6 0
2 years ago
When converted to a household measurement, 9 kilograms is approximately equal to a
Evgen [1.6K]

Answer:

D) 19.8 lbs

Explanation:

1kg in household measurement is equal to 35.274 ounces. 35.274*9=317.466 ounces.

1kg is also equal to 2.205 lbs. 9*2.205=19.8416

9 kg is also equal to 9000 grams, but grams are not a part of the household measurement system

a) 9000 grams. b) 9000 ounces. c) 19.8 ounces. d) 19.8 pounds.

This leaves us with 19.8lbs

3 0
2 years ago
Using the criteria you described in your previous answer, how would you compare solar power to fossil fuel power?
Scilla [17]

Solar power differ to fossil fuel power in that solar power is a much more optimal resource than fossil fuels

  • Solar power; however provides much more energy than fossil fuel power
  • Interestingly too, solar power resource can be used without releasing greenhouse gases compared to fossil fuels power
  • Infact, solar energy is the most reliable

<h3>What is renewable energy?</h3>

Renewable energy simply refers to energy that is not depleted when used. An example of such is solar power.

So therefore, solar power differ to fossil fuel power in that solar power is a much more optimal resource than fossil fuels

Learn more about renewable energy:

brainly.com/question/79953

#SPJ1

6 0
1 year ago
Unpolarized light of intensity I=10 falls on two successive polarizer wheels with the angle between the polarizer wheels e-60°.
yan [13]

Answer:

I=\frac{10}{4}

Explanation:

A polarizer changes the orientation of the oscillations of a light wave.

I₀ = Intensity of unpolarized light = 10

θ = Angle given to the polarizer = 60°

Intensity of light

I = I₀cos²θ

⇒I = 10cos²60

\\\Rightarrow I=10\times \frac{1}{2}\times \frac{1}{2}\\\Rightarrow I=\frac{10}{4}

So, the after passing through the second polarizer is \mathbf{\frac{10}{4}}

5 0
3 years ago
Which defintion of heat is most scientifically accurate
lukranit [14]
Hi there

Definition of heat

the quality of being hot; high temperature.
6 0
2 years ago
Other questions:
  • K-2/5=11k literal equations
    9·1 answer
  • In each of two coils the rate of change of the magnetic flux in a single loop is the same. The emf induced in coil 1, which has
    9·2 answers
  • What is the relationship between environmental science and public policymakers?
    7·1 answer
  • What is the relationship between frequency ad wavelenght
    6·2 answers
  • Total amount of kinetic and potential energy in a system ​
    11·1 answer
  • Describe the effect of the amplitude on the velocity of the pulse!???
    10·1 answer
  • Two point charges, the first with a charge of 4.47 x 10-6 C and the second with a charge of 1.86 x 10-6 C, are separated by 17.4
    11·2 answers
  • Why is an element considered a pure substance?
    12·1 answer
  • How did the discovery of eris force astronomers to reconsider the definition of planet?
    7·1 answer
  • Two objects with a mass of 10,000-kg each and a distance of 1 meter between them.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!