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2 months ago

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A gymnast spring vertical upward from a trampoline as in figure. The gymnast leaves the trampoline at height of 1.20m and reache

s a maximum height of 4.80m before falling back down. all heights are all measured with respect to the ground. Ignoring air resistance, determine the initial speed “vo” with witch the gymnast leaves the trampoline.

1 answer:

Softa [3K]2 months ago

4 0

Answer:

The initial speed of the gymnast is 8.5 m/s.

Explanation:

We will employ the kinematic equation

$v_f^2= v_o^2+2ad$

to determine the gymnast’s initial speed $v_o$ .

At the peak height of his jump, the distance traveled is $d = 4.8m- 1.2m = 3.6 m$ , and his speed is zero; thus, $v_f =0$ .

Consequently, we have

$0 = v_0^2+2(-10m/s^2)(3.6m)$

$v_0^2=72m^2/s^2$

$\boxed{v_0= 8.5m/s}$

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A string is stretched by two equal but opposite forces f newton each what is tension in string

Maru [3345]

The string does not experience any force of tension, as it balances two forces acting in the same direction. Hence, the tension is zero.

Explanation:

If tension existed in the string, it would mean that two equal but opposite forces are exerting pull in contrary directions.

When a force of f newtons is applied from the right and another force of f newtons from the left, the resulting action occurs through one force. Because there is action on the same string in opposing directions, the tension in the string can only be equal to the magnitude of the string itself.

Therefore, the string indeed has no tension since it is dealing with two forces acting in the same direction. Thus, the tension is zero.

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2 months ago

A motorcycle traveling at 36 m/s slams on the brakes to avoid an accident. The motorcycle skids 23m before stoping. What is the

ValentinkaMS [3465]

Since the motorcycle was at a speed of 36 m/s prior to braking, that marks the initial velocity.
$u = 36 {ms}^{ - 1}$
The motorcycle skidded 23m before coming to a full stop, indicating that
$s = 23m$
As it has ceased motion, the final velocity is zero.

$v = 0{ms}^{ - 1}$
We can apply the 'suvat' formula relevant to linear motion.

${v}^{2} = {u}^{2} + 2as$
Substituting the aforementioned values allows us to find,

${0}^{2} = {36}^{2} + 2a(23)$

$0 = 1296+ 46a$
$46a = - 1296$
$a = - 28.2 {ms}^{ - 2}$

We can apply the formula
$v = u + at$
to calculate the time required for the motorcycle to stop.

$0 = 36 + - 28.2t$
$- 36 = - 28.2t$
$t = 1.3s$

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2 months ago

Scientists often use models to study the movement of continents. Why might scientists use a model to show this movement? A. Extr

Maru [3345]

For many years, paleontologists have maintained that the extinction of dinosaurs was primarily due to climate changes linked to gradual shifts in the arrangement of continents and oceans as a consequence of plate tectonics. Throughout the Cretaceous period, which marked the peak of dinosaur existence, extensive shallow seas intermittently covered vast portions of land. Evidence from various geological sources, such as chemical clues found in ocean floor sediments, suggests that the climate during the Late Cretaceous was warmer and more stable compared to the present. The daytime temperatures were moderate, as were the nighttime chills, with summers and winters being neither excessively hot nor incredibly cold. It is likely that the shallow continental seas helped regulate the air temperature nearby, maintaining a consistent climate.

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1 month ago

Read 2 more answers

A beaker containing mercury is placed inside a vacuum chamber in a laboratory. the pressure at the bottom of the beaker is 26000

inna [3103]

The density of mercury in its liquid form is
$\rho = 13.5 g/cm^3=13500 kg/m^3$

We understand that the equation determining the pressure at the base of a fluid column can be expressed through Stevin's law
$p=\rho g h$
where
$\rho$ represents the density of the liquid
g signifies the acceleration due to gravity
h indicates the height of the fluid column

Given that the pressure at the lower section of the beaker is $p=26000 Pa$ , we can manipulate the preceding formula to calculate the height of the mercury column
$h= \frac{p}{\rho g}= \frac{26000 Pa}{(13500 kg/m^3)(9.81 m/s^2)}=0.196m = 19.6 cm$

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2 months ago

A 2.40 kg stone is sliding in the +x-direction on a horizontal, frictionless surface. It collides with a 4.00 kg stone at rest.

inna [3103]

Answer:

4.32 kg.m/s

Explanation:

The 2.4 kg stone moves at a speed of 3.6 m/s with an angle of 30 degrees from the x+ direction towards y+. The momentum's y-component is calculated by multiplying its mass with its velocity in the y-direction.

$P_y = m*v_y = m*v*sin(\theta)$

$P_y = 2.4*3.6*sin(30)$

$P_y = 2.4*3.6*0.5 = 4.32 kg.m/s$

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2 months ago