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A bolt is dropped from a bridge under construction, falling 96 m to the valley below the bridge. (a) How much time does it take

irakobra [83]

Answer:

a)It takes the bolt 0.25 s to pass the last 11% of the fall.

b)When the bolt begins to fall the last 11% of the fall its velocity is -41.2 m/s.

c)The velocity of the bolt just before it reaches the ground is -43.6 m/s

Explanation:

Hi there!

a) Let´s calculate how much distance it is the last 11% of the fall:

96 m · 0.11 = 10.56 m

So, we have to find how much time it takes the bolt to pass from a height of 10.56 m to the ground.

First, let´s calculate how much time it takes the bolt to reach a height of 10.56 m. For that we can use this equation:

h = h0 + v0 · t + 1/2 · g · t²

Where:

h = height of the bolt at a time t.

h0 = initial height.

v0 = initial velocity.

t = time.

g = acceleration due to gravity.

If we consider the ground as the origin of the frame of reference, then h0 = 96 m. Since the bolt is dropped, the initial velocity is zero (v0 = 0). Then, the equation gets reduce to this:

h = h0 + 1/2 · g · t²

We have to find at which time h = 10.56 m.

10.56 m = 96 m - 1/2 · 9.8 m/s² · t²

Solving for t:

√(-2 · (10.56 m - 96 m) / 9.8 m/s²) = t

t = 4.2 s

Now that we have the time at which the bolt is located at 10.56 m above the ground, we can calculate the velocity of the bolt at that time.

The equation of velocity (v) of the bolt is the following:

v = v0 + g · t

at t = 4.2 s.

v = 0 - 9.8 m/s² · 4.2 s

v = -41.2 m/s

When the bolt begins to fall the last 11% of the fall its velocity is -41.2 m/s.

Now, we can calculate how much time it takes to fall the last 10.56 m.

The initial velocity of the bolt will be the velocity at h = 10.56 m. The initial height will be 10.56 m.

h = h0 + v0 · t + 1/2 · g · t²

We have to find the time at which h = 0 (the bolt hits the ground)

0 = 10.56 m - 41.2 m/s · t - 1/2 · 9.8 m/s² · t²

Solving the quadratic equation using the quadratic formula:

t = 0.25 s (the other solution of the quadratic equation is negative and thus discarded).

It takes the bolt 0.25 s to pass the last 11% of the fall.

Now, let´s calculate the velocity of the bolt when it reaches the ground:

v = v0 + g · t

v = -41.2 m/s - 9.8 m/s² · 0.25 s

v = -43.6 m/s

The velocity of the bolt just before it reaches the bolt is -43.6 m/s

6 0

2 years ago

Plz answer will give Brainliest answer to whoever does.

Jobisdone [24]

Answer:

A foot kicking ball.

An iPhone being charged

Explanation:

A foot kicking a ball is example of transportation of Kinetic energy

$\\ \sf\longmapsto K.E=\dfrac{1}{2}mv^2$

An iPhone being charged means the electronic energy is converted into machinery energy

6 0

2 years ago

A car with a mass of 1500 kg accelerates when the traffic light turns green. If the net force on the car is 3750 newtons, what i

timurjin [86]

Answer:

2.5 ms⁻²

Explanation:

By Newton's 2nd law,

The rate of change of momentum is directly proportional to the unbalance force applied on the object,

By that you can get the equation,

F = ma ⇒ a = F/m

where terms are in usual meaning

a = 3750/1500 = 2.5 ms⁻²

8 0

2 years ago

A sample of gas at 23°C is placed in an expandable container with a volume of 23 mL. The gas is heated and expands to a volume o

myrzilka [38]

Based on the options given, the most likely answer to this query is B) The temperature must be converted to Kelvin. Meaning, the temperature should be in SI unit.

Thank you for your question. Please don't hesitate to ask in Brainly your queries.

8 0

3 years ago

PLEASE HELP ME What does a moving charge experience when it is near a magnetic field? static friction gravity a stationary charg

attashe74 [19]

A moving charge experiences a force as it moves close to a magnetic field present in a region.

Explanation:

A charged particle when moves near a magnetic field is forced to move in a circular path. If there is a straight moving charged particle enters the region of the magnetic field, it's path is changed from straight path to the curved path.

The motion of the charged path inside or near the magnetic field will be a circular path and this circular path is due to the force experienced by the charged particle in the magnetic field.

The force experienced by the a charged particle as it moves near the magnetic field is termed as the Lorentz force. The expression for the Lorentz force experienced by the charged particle in the magnetic field is given by:

$\boxed{F_m=Q(\overrightarrow{v}\times\overrightarrow{B})}$

Here, $F_m$ is the magnetic force, $Q$ is the amount of charge, $\overrightarrow{v}$ is the velocity vector and $\overrightarrow{B}$ is the magnetic field intensity in the region.