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adelina 88 [10]

3 years ago

12

A 500g object falls off a cliff and losers 100 J from its gravitational potential energy store. if the gravitational field stren

gth g=9.8N/kg, how high is the cliff?

1 answer:

ludmilkaskok [199]3 years ago

7 0

Answer : Height, h = 20.4 m

Explanation :

It is given that,

Mass of an object, m = 500 g = 0.5 kg

Gravitational potential energy, PE = 100 J

The Gravitational potential energy is the energy which is possessed due to the height and gravity of an object. It is given as :

PE = m g h

where,

h is the height of the cliff.

$100\ J=0.5\ kg\times 9.8\ m/s^2\times h$

h = 20.40 m

So, the height of the cliff is 20.4 m.

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If the ankylosaurs starts running and accelerates at 1.3m/s^2 for 3 seconds how far does he make it before the velociraptor catc

sveta [45]

Acceleration is the change of velocity, and velocity is the change of distance. The opposite of finding change, or differentiation, is integration.

Acceleration = 1.3 m/s²

Velocity: ∫ 1.3 dx = 1.3x + c m/s

Distance: ∫ 1.3x dx = 1.3x²/2 + c m

Distance run: 1.3*3²/2 = 5.85 m

<em>What</em><em> </em><em>bad</em><em> </em><em>thing</em><em> </em><em>happened</em><em>?</em>

7 0

2 years ago

A piston of volume 0.1 m3 contains two moles of a monatomic ideal gas at 300K. If it undergoes an isothermal process and expands

seropon [69]

Answer:

the work is done by the gas on the environment -is W= - 3534.94 J (since the initial pressure is lower than the atmospheric pressure , it needs external work to expand)

Explanation:

assuming ideal gas behaviour of the gas , the equation for ideal gas is

P*V=n*R*T

where

P = absolute pressure

V= volume

T= absolute temperature

n= number of moles of gas

R= ideal gas constant = 8.314 J/mol K

P=n*R*T/V

the work that is done by the gas is calculated through

W=∫pdV= ∫ (n*R*T/V) dV

for an isothermal process T=constant and since the piston is closed vessel also n=constant during the process then denoting 1 and 2 for initial and final state respectively:

W=∫pdV= ∫ (n*R*T/V) dV = n*R*T ∫(1/V) dV = n*R*T * ln (V₂/V₁)

since

P₁=n*R*T/V₁

P₂=n*R*T/V₂

dividing both equations

V₂/V₁ = P₁/P₂

W= n*R*T * ln (V₂/V₁) = n*R*T * ln (P₁/P₂ )

replacing values

P₁=n*R*T/V₁ = 2 moles* 8.314 J/mol K* 300K / 0.1 m3= 49884 Pa

since P₂ = 1 atm = 101325 Pa

W= n*R*T * ln (P₁/P₂ ) = 2 mol * 8.314 J/mol K * 300K * (49884 Pa/101325 Pa) = -3534.94 J

5 0

3 years ago

A mechanic needs to replace the motor for a merry-go-round. The merry-go-round should accelerate from rest to 1.5 rad/s in 6.0s

pashok25 [27]

Answer:

109656.25 Nm

Explanation:

$\omega_f$ = Final angular velocity = 1.5 rad/s

$\omega_i$ = Initial angular velocity = 0

$\alpha$ = Angular acceleration

t = Time taken = 6 s

m = Mass of disk = 29000 kg

r = Radius = 5.5 m

$\omega_f=\omega_i+\alpha t\\\Rightarrow \alpha=\dfrac{\omega_f-\omega_i}{t}\\\Rightarrow \alpha=\dfrac{1.5-0}{6}\\\Rightarrow \alpha=0.25\ rad/s^2$

Torque is given by

$\tau=I\alpha\\\Rightarrow \tau=\dfrac{1}{2}mr^2\alpha\\\Rightarrow \tau=\dfrac{1}{2}29000\times 5.5^2\times 0.25\\\Rightarrow \tau=109656.25\ Nm$

The torque specifications must be 109656.25 Nm

5 0

2 years ago

10. Hamilton How long does it take Lewis travelling at 156 m.p.h to cover 16 miles?

Anvisha [2.4K]

Answer: Hello!

Lewis is travelling at 165 mph, which means miles per hour, this says that he does 165 miles in one hour.

We want to know how much time takes to cover 16 miles.

this can be calculated as the quotient of the distance and the velocity; this is:

$t = \frac{16 mi}{165 mi/h} = 0.096 h$

if we want to write this in minutes, then:

we know that one hour has 60 minutes, then 0.096 hours has:

0.096h*60mins/1h = 5.8 minutes.

then Lewis needs 5.8 minutes in order to cover 16 miles if his speed is 156 miles per hour.

6 0

3 years ago

Read 2 more answers

You are observing a spacecraft moving in a circular orbit of radius 100,000 km around a distant planet. You happen to be located

Natalija [7]

To solve this problem we will apply the concepts related to centripetal acceleration, which will be the same - by balance - to the force of gravity on the body. To find this acceleration we must first find the orbital velocity through the Doppler formulas for the given periodic signals. In this way:

$v_{o} = c (\frac{\lambda_{max}-\bar{\lambda}}{\bar{\lambda}}})$

Here,

$v_{o} =$ Orbital Velocity

$\lambda_{max} =$ Maximal Wavelength

$\bar{\lambda}} =$ Average Wavelength

c = Speed of light

Replacing with our values we have that,

$v_{o} = (3*10^5) (\frac{3.00036-3}{3})$

<em>Note that the average signal is 3.000000m</em>

$v_o = 36 km/s$

Now using the definition about centripetal acceleration we have,

$a_c = \frac{v^2}{r}$

Here,

v = Orbit Velocity

r = Radius of Orbit

Replacing with our values,

$a = \frac{(36km/s)^2}{100000km}$

$a= 0.01296km/s^2$

$a = 12.96m/s^2$

Applying Newton's equation for acceleration due to gravity,

$a =\frac{GM}{r^2}$

Here,

G = Universal gravitational constant

M = Mass of the planet

r = Orbit

The acceleration due to gravity is the same as the previous centripetal acceleration by equilibrium, then rearranging to find the mass we have,

$M = \frac{ar^2}{G}$

$M = \frac{(12.96)(100000000)^2}{ 6.67*10^{-11}}$

$M = 1.943028*10^{27}kg$

Therefore the mass of the planet is $1.943028*10^{27}kg$

7 0

3 years ago