What is tarzan's speed vf just before he reaches jane? express your answer in meters per second to two significant figures?

1 answer:

3 0

Before swinging, T has only potential energy, (no speed)
Ui = mgh
Where h is the vertical displacement of T
From the laws of geometry,
cos45 = (L-h)/L
cos45 = 1-h/L
h/L = 1-cos45
h = L(1-cos45)

Therefore
Ui = mgL(1-cos45)

Proceeding the same way,
Twill raise to aheight of h' due to swing
h' = L(1-cos30)
The PE of T after swing is
Uf = mgh'
Uf = mgL(1-cos30)

Along with the PE , T has some kinetic energy results due to the moment.
Tf = 0.5*mv^2

According to the law of conservation of energy,
Ui = Uf+Tf
mgL(1-cos45) = mgL(1-cos30) + 0.5*mv^2
gL(co30-cos45) = 0.5*v^2
9.8*20*(co30-cos45) = 0.5*V^2
v = 7.89 m/s

The speed f T after swing is 7.89 m/s

You might be interested in

Tyler drives 50km north. Tyler then drives back 30km south. What distance did he cover? What was his displacement?

Luda [366]

Answer:

he covered 80km his displacement was 20km

Explanation:

displacement is the distance from the starting point so in this case its 20 (50-30) and total distance covered is how many kilometers he drove in total

7 0

1 year ago

Which phenomena did Michael Faraday explore to help him invent the motor and the generator? A. motion and magnetism B. motion an

Vladimir [108]

D. electricity and magnetism

Explanation:

Michael was an English Chemist and Physicist.
His studies contributed to the inventions of electromagnetic interaction.
He found that using electricity, magnetism can be induced and that magnetism can also produce electricity.
A motor simply converts electrical energy into mechanical energy.
Generators converts chemical energy int electrical energy.
A motor and generator works based on the principle of electromagentic induction.

Learn more:

Electrolysis brainly.com/question/4609389

#learnwithBrainly

3 0

2 years ago

Read 2 more answers

About three billion years ago, single-celled organisms called cyanobacteria lived in Earth’s oceans. They thrived on the ocean’s

pickupchik [31]

I think its Oxygen.
ancient cyanobacteria produced Earth's first oxygen-rich atmosphere, which allowed the eventual rise of eukaryotes. The chloroplasts of eukaryotic algae and plants are derived from cyanobacteria

3 0

2 years ago

Read 2 more answers

In the sum of 54.34 and 45.66, the number of significant figure for the answer is

Natali5045456 [20]

Answer:

Explanation:

54.34+45.66=100.00 (you have to use the .00 because when you add to numbers you keep the number of decimals)

so you get 100.00

all numbers that are not 0 are sig figs so 1 is a sig fig

If a number ends with a 0 after a decimal place that 0 is a sig fig

all numbers between two sig figs are sig figs so that would make all of the numbers sig figs

4 0

2 years ago

When photons with a wavelength of 310. nm strike a magnesium plate, the maximum velocity of the ejected electrons is 3.45 105 m/

Kisachek [45]

This problem can be solved based on the rule of energy conservation, as the energy of the photon covers both the energy needed to overcome the binding energy as well as the energy of ejection.

The rule can be written as follows:
energy of photon = binding energy + kinetic energy of ejectection
(hc) / lambda = E + 0.5 x m x v^2 where:
h is plank's constant = 6.63 x 10^-34 m^2 kg / s
c is the speed of light = 3 x 10^8 m/sec
lambda is the wavelength = 310 nm
E is the required binding energy
m is the mass of photon = 9.11 x 10^-31 kg
v is the velocity = 3.45 x 10^5 m/s

So, as you can see, all the parameters in the equation are given except for E. Substitute to get the required E as follows:
(6.63x10^-34x3x10^8)/(310x10^-9) = E + 0.5(9.11 x 10^-31)(3.45x10^5)^2
E = 6.41 x 10^-16 joule

To get the E in ev, just divide the value in joules by 1.6 x 10^-19
E = 4.009 ev

3 0

2 years ago