All categories

3 years ago

A 50 N girl climbs the flight of stairs in 3 seconds. How much work does she

1 answer:

7 0

She uses 0 power because she simply has no gas left. She used all of it getting a 50 pc McDonald’s nugget with a side of ranch and a medium fry and a large water.

You might be interested in

On a color wheel, colors that are directly across from each other are called _______ colors.

Salsk061 [2.6K]

I believe the answer is : A

4 0

3 years ago

I drop an egg from a certain distance and it takes 3.74 seconds to reach the ground. How high up was the egg?

OverLord2011 [107]

Answer:

68.5 meters

Explanation:

Given:

v₀ = 0 m/s

a = 9.8 m/s²

t = 3.74 s

Find: Δy

Δy = v₀ t + ½ at²

Δy = (0) (3.74) + ½ (9.8) (3.74)²

Δy = 68.5

The egg fell 68.5 meters.

7 0

3 years ago

5. Which of these affect the brightness of a bulb? Choose all that apply.* 6 po

schepotkina [342]

Answer:

The voltage of the battery

7 0

3 years ago

________ reaction time involves selecting a specific and correct response from several choices when presented with several diffe

lukranit [14]

Simple reaction time involves selecting a specific and correct response from several choices when presented with several different stimuli. This is very important because historically, this was the first indicators of intelligence pioneered by Francis Galton. To measure one’s intelligence is to know how he quick a person could respond to the stimulus with an already expected response wherein the stimulus is given unknown to the receiver. In other terms, the intelligence is measured on how quick a person could grasp certain concepts and how he could think fast and answer them correctly. <span> </span>

4 0

3 years ago

Read 2 more answers

A loaded 375 kg toboggan is traveling on smooth horizontal snow at 4.50 m/s when it suddenly comes to a rough region. The region

zmey [24]

Answer:

a) The average friction force exerted on the toboggan is 653.125 newtons, b) The rough region reduced the kinetic energy of the toboggan in 92.889 %, c) The speed of the toboggan is reduced in 73.333 %.

Explanation:

a) Given the existence of non-conservative forces (friction between toboggan and ground), the motion must be modelled by means of the Principle of Energy Conservation and the Work-Energy Theorem, since toboggan decrease its speed (associated with due to the action of friction. Changes in gravitational potential energy can be neglected due to the inclination of the ground. Then:

$K_{1} = K_{2} + W_{f}$

Where:

$K_{1}$ , $K_{2}$ are the initial and final translational kinetic energies of the tobbogan, measured in joules.

$W_{f}$ - Dissipated work due to friction, measured in joules.

By applying definitions of translation kinetic energy and work, the expression described above is now expanded and simplified:

$f\cdot \Delta s = \frac{1}{2}\cdot m \cdot (v_{1}^{2}-v_{2}^{2})$

Where:

$f$ - Friction force, measured in newtons.

$\Delta s$ - Distance travelled by the toboggan in the rough region, measured in meters.

$m$ - Mass of the toboggan, measured in kilograms.

$v_{1}$ , $v_{2}$ - Initial and final speed of the toboggan, measured in meters per second.

The friction force is cleared:

$f = \frac{m\cdot (v_{1}^{2}-v_{2}^{2})}{2\cdot \Delta s}$

If $m = 375\,kg$ , $v_{1} = 4.50\,\frac{m}{s}$ , $v_{2} = 1.20\,\frac{m}{s}$ and $\Delta s = 5.40 \,m$ , then:

$f = \frac{(375\,kg)\cdot \left[\left(4.50\,\frac{m}{s} \right)^{2}-\left(1.20\,\frac{m}{s}\right)^{2}\right]}{2\cdot (5.40\,m)}$

$f = 653.125\,N$

The average friction force exerted on the toboggan is 653.125 newtons.

b) The percentage lost by the kinetic energy of the tobbogan due to friction is given by the following expression, which is expanded and simplified afterwards:

$\% K_{loss} = \frac{K_{1}-K_{2}}{K_{1}}\times 100\,\%$