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2 years ago

A fire woman dropped a person onto the safety net. Right

Physics

1 answer:

dolphi86 [110]2 years ago

7 0

Answer:

m = 28.7[kg]

Explanation:

To solve this problem we must use the definition of kinetic energy, which can be calculated by means of the following equation.

$E_{k}=\frac{1}{2}*m*v^{2}\\$

where:

Ek = kinetic energy = 1800 [J]

m = mass [kg]

v = 11.2 [m/s]

$1800=\frac{1}{2}*m*(11.2)^{2}\\m = 28.7[kg]$

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Five race cars speed toward the finish line at the Jasper County Speedway. The table lists each car’s speed in meters/second. If

Anarel [89]

I think the answer would be Car C.

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2 years ago

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Your friend wants to join the school track team, and has asked for your help to determine how fast she can run. What kind of inf

Zigmanuir [339]

Answer:

you calculate a specific type of run for example 100m and it takes 20 seconds to finish and calculate the time it takes them to finish

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Explanation:

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2 years ago

A child throws a ball vertically upward to a friend on a balcony 28 m above him. The friend misses the ball on its upward flight

photoshop1234 [79]

Answer:

$t=1.9 sec$

Explanation:

From the question we are told that:

Height $h=28m$

Time $t=3s$

Generally the Newton's equation for Initial velocity upward is mathematically given by

$s=ut+\frtac{1}{2}at^2$

$28=3u-\frac{1}{2}*9.8*3^2$

$u=24.03m/s$

Generally the velocity at elevation and depression occurs as ball arrives and passes through S=28

$v=\sqrt{24.03-2*9.8*28}$

$v=5.35m/s and -5.35m/s$

Generally the Newton's equation for time to reach initial velocity is mathematically given by

$v=u+at$

$5.35=24.03-9.8t$

$t=\frac{28.03-5.35}{9.8}$

$t=1.9 sec$

4 0

2 years ago

A motorcycle starts from rest and has a constant acceleration. In a time interval t, it undergoes a displacement x and attains a

iren [92.7K]

Answer:

√(6ax)

Explanation:

Hi!

The question states that during a time t the motorcyle underwent a displacement x at constant acceleration a starting from rest, mathematically we can express it as:

x=(1/2)at^2

Then the we need to find the time t' for which the displacement is 3x

3x=(1/2)a(t')^2

Solving for t':

t'=√(6x/a)

Now, the velocity of the motorcycle as a function of time is:

v(t)=a*t

Evaluating at t=t'

v(t')=a*√(6x/a)=√(6*x*a)

Which is the final velocity

Have a nice day!

3 0

3 years ago

If the bonds in the reactants of Figure 7-3 contained 432 kJ of chemical energy and the bonds in the

Yuri [45]

Answer:

The energy change would be 46kJ

The energy would be absorbed

Explanation:

The energy change during a chemical reation, i.e. the reaction energy, is equal to the chemical energy stored in the bonds of the products less the chemical energy stored in the bonds of the reactants.

Hence:

Energy change = 478 kJ - 432kJ = 46kJ

The change is positive, this is, the chemical energy of the products is greater than the chemical energy of the reactants.

That corresponds to the second graph, where the level of the energy of the products in the graph is higher than the level of the energy of the reactants. Therefore, the conclusion is that the reaction absorbed energy and it is endothermic.

4 0

3 years ago