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3 years ago

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HELPPPPPPPPPPP PLEASE 25 points!!!!

1 answer:

Contact [7]3 years ago

7 0

This simply states that energy cannot be created or destroyed, it can only be transferred from one form to another. ... This dissipated heat energy cannot be regained in a useful form. Fuels. A fuel releases energy when it undergoes a chemical reaction.

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The greatest height reported for a jump into an airbag is 99.4 m by stuntman Dan Koko. In 1948 he jumped from rest from the top

leva [86]

Answer:

44.1613858478 m/s

Explanation:

t = Time taken

u = Initial velocity = 0

v = Final velocity

s = Displacement = 99.4

a = Acceleration

g = Acceleration due to gravity = 9.81 m/s² = a

$v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times 9.81\times 99.4+0^2}\\\Rightarrow v=44.1613858478\ m/s$

If air resistance was absent Dan Koko would strike the airbag at 44.1613858478 m/s

6 0

2 years ago

During a tornado in 2008 the Peachtree Plaza Westin Hotel in downtown Atlanta suffered damage. Suppose a piece of glass dropped

Darina [25.2K]

Answer:

Time = t = 6.62 s

Explanation:

Given data:

Height = h = 215 m

Initial velocity = $v_{i}$ = 0 m/s

gravitational acceleration = g = 9.8 m/s²

Time = t = ?

According to second equation of motion

$h = v_{i}t + \frac{1}{2}gt^{2}$

As initial velocity is zero, So the first term of right hand side of above equation equal to zero.

$h = \frac{1}{2}gt^{2}$

t² = $\frac{2h}{g}$

t = $\sqrt{\frac{2h}{g} }$

t = $\sqrt{\frac{(2)(215) }{9.8} }$

t = 6.62 s

3 0

3 years ago

Five hundred joules of heat are added to a closed system. The initial internal energy of the system is 87 J, and the final inter

mina [271]

The answer is D. i got all the other ones wrong ._.

8 0

3 years ago

Read 2 more answers

A rectangular sharp-crested weir is contracted on both sides, and the opening is 1.2 m wide. At what height (Hw) should it be pl

Alex

Answer:

H_w = 2.129 m

Explanation:

given,

Width of the weir, B = 1.2 m

Depth of the upstream weir, y = 2.5 m

Discharge, Q = 0.5 m³/s

Weir coefficient, C_w = 1.84 m

Now, calculating the water head over the weir

$Q = C_w BH^{3/2}$

$H = (\dfrac{Q}{C_wB})^{2/3}$

$H = (\dfrac{0.5}{1.84\times 1.2})^{2/3}$

$H = 0.371\ m$

now, level of weir on the channel

H_w = y - H

H_w = 2.5 - 0.371

H_w = 2.129 m

Height at which weir should place is equal to 2.129 m.

7 0

3 years ago

75kg man climbs a mountain 1000m high in 3hrs and uses 4100 joulse/min. (a) calculate the power consumption in watt, (b) what is

mr Goodwill [35]

Answer:

Explanation:

a) Power consumption is 4100 J/min / 60 s/min = 68.3 W(atts)

work done raised the potential energy

b) 75(9.8)(1000) / (3(3600)) = 68.055555... 68.1 W

c) efficiency is 68.1 / 68.3 = 0.99593... or nearly 100%

Not a very likely scenario.

3 0

3 years ago