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3 years ago

I don’t understand this question

Physics

1 answer:

hichkok12 [17]3 years ago

6 0

It's Z.

Without any force acting on it an object travels in a straight line.

In order to bend away from a straight line the object needs a force acting on it.

In order to move along a circle, the force on the object points toward the center of the circle. It's called the centripetal force.

Since the object's direction is changing it has acceleration.

The acceleration points toward the center of the circle.

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What represents a case in which you are not accelerating?

KIM [24]

Answer: dv/dt = 0

Explanation: Acceleration has to do with when you are changing velocity. since velocity is a speed and a direction you only accelerate when you change speed or change direction or change both in other words you are not accelerating when you are moving in a constant speed and at a specified direction. E.g driving Eastward at a constant speed of 24m/s, such scenario is a case of not accelerating that is acceleration is zero.

4 0

4 years ago

A 3.00 m-long 6.00-kg ladder pivoted at the top hangs down from a platform at the circus. A 42.0-kg trapeze artist climbs to a p

statuscvo [17]

Answer:

The period of the system of ladder and woman, T = 2.5 seconds

Explanation:

Mass of the ladder, $m_1 = 6 kg$

Mass of the artiste, $m_2 = 42.0 kg$

Length of the ladder, L = 42.0 kg

The total moment of inertia can be calculated using the equation:

$I = \frac{1}{3} M_1 L^2 + m_2 (\frac{L}{2} )^2\\I = \frac{1}{3} *6*3^2 + 42* (\frac{3}{2} )^2\\I = 18 + 94.5\\I = 112.5 kg m^2$

D = L/2 = 3/2

D = 1.5 m

The frequency of the system of ladder and woman follows that of a physical pendulum which can be given by the equation:

$f = \frac{1}{2\pi } \sqrt{\frac{mgD}{I} } \\f = \frac{1}{2\pi } \sqrt{\frac{48*9.8*1.5}{112.5} }\\f = 0.4$

The period of the system of ladder and woman is given by:

T = 1/f

T = 1/0.4

T = 2.5 seconds

5 0

3 years ago

A block of ice(m = 14.0 kg) with an attached rope is at rest on a frictionless surface. You pull the block with a horizontal for

nadezda [96]

Answer:

a) The weight and the normal force of the block has a magnitude of 137.298 newtons and the pull force exerted on the block has a magnitude of 98 newtons.

b) The final speed of the block of ice is 9.8 meters per second.

Explanation:

a) We need to calculate the weight, normal force from the ground to the block and the pull force. By 3rd Newton's Law we know that normal force is the reaction of the weight of the block of ice on a horizontal.

The weight of the block ( $W$ ), measured in newtons, is:

$W = m\cdot g$ (1)

Where:

$m$ - Mass of the block of ice, measured in kilograms.

$g$ - Gravitational acceleration, measured in meters per square second.

If we know that $m = 14\,kg$ and $g = 9.807\,\frac{m}{s^{2}}$ , the magnitudes of the weight and normal force of the block of ice are, respectively:

$N = W = (14\,kg)\cdot \left(9.807\,\frac{m}{s^{2}} \right)$

$N = W = 137.298\,N$

And the pull force is:

$F_{pull} = 98\,N$

The weight and the normal force of the block has a magnitude of 137.298 newtons and the pull force exerted on the block has a magnitude of 98 newtons.

b) Since the block of ice is on a frictionless surface and pull force is parallel to the direction of motion and uniform in time, we can apply the Impact Theorem, which states that:

$m\cdot v_{o} +\Sigma F \cdot \Delta t = m\cdot v_{f}$ (2)

Where:

$v_{o}$ , $v_{f}$ - Initial and final speeds of the block, measured in meters per second.

$\Sigma F$ - Horizontal net force, measured in newtons.

$\Delta t$ - Impact time, measured in seconds.

Now we clear the final speed in (2):

$v_{f} = v_{o}+\frac{\Sigma F\cdot \Delta t}{m}$

If we know that $v_{o} = 0\,\frac{m}{s}$ , $m = 14\,kg$ , $\Sigma F = 98\,N$ and $\Delta t = 1.40\,s$ , then final speed of the ice block is:

$v_{f} = 0\,\frac{m}{s}+\frac{(98\,N)\cdot (1.40\,s)}{14\,kg}$

$v_{f} = 9.8\,\frac{m}{s}$

The final speed of the block of ice is 9.8 meters per second.

6 0

3 years ago

What is latent heat? Group of answer choices Energy released when water evaporates. Energy hidden in water vapor in the air. Ene

Andrews [41]

Answer:

Energy absorbed or hidden when water evaporates

Explanation:

The heat that is required to make a phase change is known as latent heat.

A phase change occurs when matter changes state. For example from solid to liquid, from liquid to gas, among others.

When changing from liquid to gas (for example when water evaporates), the heat necessary for this to happen is called latent heat of vaporization. The word latent means hidden, because a change in temperature is not perceived during the phase change, even when heat is being added, thus it is said that the heat is hidden or latent.

So the answer is:

Energy absorbed or hidden when water evaporates.

*Another type of latent heat is the latent heat of fusion, which is when a solid becomes liquid.

7 0

4 years ago

Can somebody please help with these

Sever21 [200]

Answer:

Fusion

Fission

Explanation:

The first problem describes a nuclear fusion process. In this process;

small atomic nuclei combines to form a larger one.
it is accompanied by a large release of energy
this energy provides the needed temperature to set up another light nuclei to fuse.

The second problem describes nuclear fission,

a heavy nuclide is bombarded with a neutron.
the product formed becomes unstable and subsequently breaks down.
This leads to a series of chain reactions until stability is attained.

6 0

3 years ago