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2 years ago

A girl lifts a 160-N load to a height of 1 m in 0.5 s. How much power is used to lift the load?

1 answer:

8 0

First, find the work done. W = f*d, so 160 N * 1 m = 160 J. Then divide the work by the time to get the power. P = W/t. P = 160 J / 0.5 s = 320 W.
The answer is 320 W. Hope this helps, and have a great day! :)

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The spring is released and a 0.10-kilogram plastic sphere is fired from the launcher. Calculate the maximum speed with which the

tigry1 [53]

Answer:

A) The elastic potential energy stored in the spring when it is compressed 0.10 m is 0.25 J.

B) The maximum speed of the plastic sphere will be 2.2 m/s

Explanation:

Hi there!

I´ve found the complete problem on the web:

A toy launcher that is used to launch small plastic spheres horizontally contains a spring with a spring constant of 50. newtons per meter. The spring is compressed a distance of 0.10 meter when the launcher is ready to launch a plastic sphere.

A) Determine the elastic potential energy stored in the spring when the launcher is ready to launch a plastic sphere.

B) The spring is released and a 0.10-kilogram plastic sphere is fired from the launcher. Calculate the maximum speed with which the plastic sphere will be launched. [Neglect friction.] [Show all work, including the equation and substitution with units.]

A) The elastic potential energy (EPE) is calculated as follows:

EPE = 1/2 · k · x²

Where:

k = spring constant.

x = compressing distance

EPE = 1/2 · 50 N/m · (0.10 m)²

EPE = 0.25 J

The elastic potential energy stored in the spring when it is compressed 0.10 m is 0.25 J.

B) Since there is no friction, all the stored potential energy will be converted into kinetic energy when the spring is released. The equation of kinetic energy (KE) is the following:

KE = 1/2 · m · v²

Where:

m = mass of the sphere.

v = velocity

The kinetic energy of the sphere will be equal to the initial elastic potential energy:

KE = EPE = 1/2 · m · v²

0.25 J = 1/2 · 0.10 kg · v²

2 · 0.25 J / 0.10 kg = v²

v = 2.2 m/s

The maximum speed of the plastic sphere will be 2.2 m/s

6 0

3 years ago

A battery is the power source for what type of current

patriot [66]

Answer: DC Current

Explanation:

Battery is a source of constant potential difference and it will create a constant voltage across any conductor

due to this constant voltage difference the current in this conductor will remain constant

So here since the voltage across the conductor is constant so we can say that current in the conductor will remain constant and hence this is known as DC current.

While for variable current in direction and magnitude is to be obtained only when the conductor is connected with AC voltage source as we know that AC voltage is variable with magnitude and direction both

A battery is the power source for DC type of current. A battery is a source of constant potential difference that produces a constant current unlike in AC source where the voltage and hence the current changes its polarity continuously.Hence, the current produced by battery is direct current and not Alternating current.

Hope this helps........ Stay safe and have a Merry Christmas!!!!!! :D

3 0

2 years ago

A child whose weight is 276 N slides down a 5.90 m playground slide that makes an angle of 34.0° with the horizontal. The coeffi

garik1379 [7]

Answer:

Explanation:

Frictional force acting on the child = μ mg cosθ

, μ is coefficient of kinetic friction , m is mass of child θ is inclination

work done by frictional force

μ mg cosθ x d , d is displacement on inclined plane

work done = .13 x 276 x cos34 x 5.9

= 175.5 J

This work will be converted into heat energy.

b ) Initial energy of child = mgh + 1/2 m v ² , h is height , v is initial velocity

= 276 x 5.9 sin34 + 1/2 x 276 / 9.8 x .518² [ mass m = 276 / g ]

= 910.59 + 3.77

= 914.36 J

loss of energy due to friction = 175.5

Net energy at the bottom

= 738.86 J

If v be the velocity at the bottom

1/2 m v² = 738 .86

.5 x (276 / 9.8) x v² = 738.86

v² = 52.47

v = 7.24 m /s .

4 0

3 years ago

Read 2 more answers

An object moving on a horizontal, frictionless surface makes a glancing collision with another object initially at rest on the s

Eddi Din [679]

Answer:

The correct answer is option 'a' 'The momentum is always conserved while as the kinetic energy may be conserved'

Explanation:

The conservation of momentum is a basic principle in nature which is always valid in an collision between 'n' number of objects if there are no external forces on the system. It is valid for both the cases weather the collision is head on or glancing or weather the object is elastic or inelastic.

The energy is only conserved in a collision that occurs on a friction less surface and the objects are purely elastic. Since in the given question it is mentioned that only the surface is friction less and no information is provided regarding the nature of the objects weather they are elastic or not hence we cannot conclusively come to any conclusion regarding the conservation of kinetic energy as the objects may be inelastic.

3 0

3 years ago

The idea that large fibers in the sensory nerves can prevent impulses from reaching the brain and thus prevent the sensation of

allochka39001 [22]

Answer:

Gate control theory of pain

Explanation:

The gate control theory of pain sates that non-painful input closes the nerve gates to painful input, which prevents pain sensation from traveling to the central nervous system (brain).

Therefore, the idea that large fibers in the sensory nerves can prevent impulses from reaching the brain and thus prevent the sensation of pain is part of the gate control theory of pain.

4 0

3 years ago