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2 years ago

If a rock falls from a cliff, at what point are its kinetic energy and its potential energy the same? Ignore air resistance.

Physics

2 answers:

nekit [7.7K]2 years ago

6 0

Answer:

The gravitational potential energy it had from being above the ground is converted to kinetic energy as the rock falls. As kinetic energy increases, the velocity of the rock will also increase.

Explanation:

Pavlova-9 [17]2 years ago

4 0

I think its the whole time they are falling

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A swimming pool has the shape of a box with a base that measures 21 m by 14 m and a depth of 3.1 m. how much work is required to

Lynna [10]

The work needed to pump the water would have the units of Joules or Pa*m^3. From here, this would be a hint that you only multiply the hyraulic pressure and its volume.

Hydraulic pressure = density*gravity*height = 1000*9.8*3.1 = 30,411 Pa
Volume = 21*14*3.1 = 911.4 m^3
Work = 30,411*911.4 = 27,716,585.4 J = 27.72 MJ

5 0

3 years ago

"Find the total weight of an 18-ft3 tank of oxygen if the oxygen is pressurized to 184 psia, the tank itself weighs 150 lbf, and

Fiesta28 [93]

Answer:

Explanation:

1 psi = 6894.76 Pa

P = 184 psi = 12.686 x 10⁵ Pa .

Temperature T = 95⁰F = 35⁰C= 308 K

volume V = 18 ft³ = 18 x 0.0283168 m³

= .51 m³

From the gas law

PV/RT = n where n is mole of gas

= 12.686 x 10⁵ x .51 / 8.31 x 308

= 252.78 gm mole

= 252.78 x 32 gm

= 8.08896 kg

= 2.20462 x 8.08896 lb

= 17.833 lb

= 17.833 / 32 lbf

= .5573 lbf

weight of tank = 150 lbf

Total weight = 150 + .5573

= 150.5573 lbf .

7 0

3 years ago

. Using your knowledge of circular (centripetal) motion, derive an equation for the radius r of the circular path that electrons

Ronch [10]

Answer:

Explanation:

Magnetic field creates a force perpendicular to a moving charge in its field which is equal to Bev where B is magnetic field , e is amount of charge on the moving charge and v is the velocity of charge particle .

This force provides centripetal force for creation of circular motion. If r be the radius of the circular path

Bev = mv² / r

r = mv / Be

2 ) If an electron is accelerated by an electric field created by potential difference V then electric field

= V / d where d is distance between two points having potential difference v .

force on charged particle

electric field x charge

= V /d x e

work done by field

= force x distance

= V /d x e x d

V e

This is equal to kinetic energy created

V e = 1/2 mv²

= 1/2 m (r²B²e² / m² )

V = r²B²e/ 2 m

e / m = 2 V/ r²B²

3 )

B = $\frac{\mu\times I\times R^2}{2(R^2+Z^2)^\frac{3}{2} }$

In Helmholtz coils , distance between coil is equal to R so Z = R/2

B = $\frac{\mu\times I\times R^2}{2(R^2+\frac{R^2}{4} )^\frac{3}{2} }$

For N turns of coil and total field due to two coils

B = $\frac{\mu\times I\times N}{R\times(\frac{5}{4})^\frac{3}{2} }$

= $\frac{\mu\times I\times N}{R}\times (\frac{4}{5})^\frac{3}{2}$

= 9.0 x 10^-7 NI/R

8 0

4 years ago

Please explain it’s in the photo

Leto [7]

Answer:

Since air resistance actually stops vehicles and goes in a vector opposite to the direction of the vehicle and slows it down. Vehicles would want to make vehicles aerodynamic. Many cars bump into air molecules therefore making air resistance. Aerodynamic cars will lesser the allowance of bumping into said molecules. Thats why cars like to cut down on air resistance

4 0

4 years ago

Read 2 more answers

A 1459 kg car is traveling WEST at 43 m/s. A 9755 kg truck is traveling EAST at 11 m/s. They collide head-on, and stick together

otez555 [7]

Answer:

<em>Both vehicles move east at 3.97 m/s</em>

Explanation:

<u>Law Of Conservation Of Linear Momentum </u>

It states that the total momentum of a system of bodies is conserved unless an external force is applied to it. The formula for the momentum of a body with mass m and speed v is:

P=mv.

If we have a system of two bodies, then the total momentum is the sum of both momentums:

$P=m_1v_1+m_2v_2$

If a collision occurs and the velocities change to v', the final momentum is:

$P'=m_1v'_1+m_2v'_2$

Since the total momentum is conserved, then:

P = P'

$m_1v_1+m_2v_2=m_1v'_1+m_2v'_2$

Assume both masses stick together after the collision at a common speed v', then:

$m_1v_1+m_2v_2=(m_1+m_2)v'$

The common velocity after this situation is:

$\displaystyle v'=\frac{m_1v_1+m_2v_2}{m_1+m_2}$

Assuming east direction to be positive, we have an m1=1459 kg car traveling west at v1=-43 m/s. An m2=9755 kg truck is traveling east at v2=11 m/s. They collide head-on and stick together after that.

Computing the resultant velocity after the collision:

$\displaystyle v'=\frac{1459*(-43)+9755*11}{1459+9755}$

$\displaystyle v'=\frac{44568}{11214}$

v' = 3.97 m/s

Both vehicles move east at 3.97 m/s

4 0

3 years ago