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3 years ago

Please help ASAP!!

1 answer:

6 0

There is kinetic energy when it is sitting at the top, then as it goes towards the bottom, the kinetic energy is transformed into potential energy.

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An ideal gas is in a sealed rigid container. the average kinetic energy of the gas molecules depends most on

finlep [7]

It depends most on the temperature of the gas.

8 0

3 years ago

Suzanne notices that when sunlight strikes the surface of a calm lake, it creates a glare. Which statement accurately describes

kumpel [21]

<span>The answer is C. This is called polarization of light by reflection. The sunlight is reflected at a parallel angle from on the surface plane of the water from which it bounces from. The glare is due to this polarization of sun beams at an angle with respect to the viewer. </span>

4 0

3 years ago

1.A river flowing steadily at a rate of 240 m3/s is considered for hydroelectric power generation. It is determined that a dam c

SIZIF [17.4K]

Answer:

the power that can be generated by the river is 117.6 MW

Explanation:

Given that;

Volume flow rate of river v = 240 m³/s

Height above the lake surface a h = 50 m

Amount of power can be generated from this river water after the dam is filled = ?

Now the collected water in the dam contains potential energy which is used for the power generation,

hence, total mechanical energy is due to potential energy alone.

$E_{mech}$ = m(gh)

first we determine the mass flow rate of the fluid m

m = p×v

where p is density ( 1000 kg/m³

so we substitute

m = 1000kg/m³ × 240 m³/s

m = 240000 kg/s

so we plug in our values into ( $E_{mech}$ = m(gh) kJ/kg )

$E_{mech}$ = 240000 × 9.8 × 50

$E_{mech}$ = 117600000 W

$E_{mech}$ = 117.6 MW

Therefore, the power that can be generated by the river is 117.6 MW

4 0

3 years ago

A car is designed to get its energy from a rotating flywheel with a radius of 1.50 m and a mass of 430 kg. Before a trip, the fl

fiasKO [112]

Answer:

$KE = 7.17 *10^{7} \ J$

$t = 6411.09 \ s$

Explanation:

From the question we are told that

The radius of the flywheel is $r = 1.50 \ m$

The mass of the flywheel is $m = 430 \ kg$

The rotational speed of the flywheel is $w = 5,200 \ rev/min = 5200 * \frac{2 \pi }{60} =544.61 \ rad/sec$

The power supplied by the motor is $P = 15.0 hp = 15 * 746 = 11190 \ W$

Generally the moment of inertia of the flywheel is mathematically represented as

$I = \frac{1}{2} mr^2$

substituting values

$I = \frac{1}{2} ( 430)(1.50)^2$

$I = 483.75 \ kgm^2$

The kinetic energy that is been stored is

$KE = \frac{1}{2} * I * w^2$

substituting values

$KE = \frac{1}{2} * 483.75 * (544.61)^2$

$KE = 7.17 *10^{7} \ J$

Generally power is mathematically represented as

$P = \frac{KE}{t}$

=> $t = \frac{KE}{P}$

substituting the value

$t = \frac{7.17 *10^{7}}{11190}$

$t = 6411.09 \ s$

3 0

3 years ago

A child bounces a 48 g superball on the sidewalk. the velocity change of the superball is from 26 m/s downward to 17 m/s upward.

Nataly_w [17]

By definition we have the momentum is:
P = m * v
Where,
m = mass
v = speed
Before the impact:
P1 = (0.048) * (26) = 1.248 kg * m / s
After the impact:
P2 = (0.048) * (- 17) = -0.816 Kg * m / s.
Then we have that deltaP is:
deltaP = P2-P1
deltaP = (- 0.816) - (1,248)
deltaP = -2,064 kg * m / s.
Then, by definition:
deltaP = F * delta t
Clearing F:
F = (deltaP) / (delta t)
Substituting the values
F = (- 2.064) / (1/800) = - 1651.2N
answer:
the magnitude of the average force exerted on the superball by the sidewalk is 1651.2N

3 0

4 years ago