7-10/2 A.2 B.-13 C.12

How much work can be done by a 50w motor in 5 sec?

Vaselesa [24]

A 50w motor can do 500w in 5 seconds

4 0

3 years ago

A butterfly flies from the top of a tree in the center of a garden to rest on top of a red flower at the garden's edge. The tree

Zielflug [23.3K]

The butterfly takes a vertical perpendicular path equivalent to 9m and travels a horizontal distance of 17m. The net path between the two is equivalent to that of the hypotenuse, so we will apply the Pythagorean theorem.

$x=\sqrt{(9)^2+(0.17)^2}$

$x = 9.0061 \approx 9.0 m$

Therefore the magnitude of the butterfly's displacement is 9m

3 0

2 years ago

Read 2 more answers

A 3.5 kg object moving in two dimensions initially has a velocity v1 = (12.0 i^ + 22.0 j^) m/s. A net force F then acts on the o

lys-0071 [83]

Answer:

The work done by the force is 820.745 joules.

Explanation:

Let suppose that changes in potential energy can be neglected. According to the Work-Energy Theorem, an external conservative force generates a change in the state of motion of the object, that is a change in kinetic energy. This phenomenon is describe by the following mathematical model:

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

Where:

$W_{F}$ - Work done by the external force, measured in joules.

$K_{1}$ , $K_{2}$ - Translational potential energy, measured in joules.

The work done by the external force is now cleared within:

$W_{F} = K_{2} - K_{1}$

After using the definition of translational kinetic energy, the previous expression is now expanded as a function of mass and initial and final speeds of the object:

$W_{F} = \frac{1}{2}\cdot m \cdot (v_{2}^{2}-v_{1}^{2})$

Where:

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

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

Now, each speed is the magnitude of respective velocity vector:

Initial velocity

$v_{1} = \sqrt{v_{1,x}^{2}+v_{1,y}^{2}}$

$v_{1} = \sqrt{\left(12\,\frac{m}{s} \right)^{2}+\left(22\,\frac{m}{s} \right)^{2}}$

$v_{1} \approx 25.060\,\frac{m}{s}$

Final velocity

$v_{2} = \sqrt{v_{2,x}^{2}+v_{2,y}^{2}}$

$v_{2} = \sqrt{\left(16\,\frac{m}{s} \right)^{2}+\left(29\,\frac{m}{s} \right)^{2}}$

$v_{2} \approx 33.121\,\frac{m}{s}$

Finally, if $m = 3.5\,kg$ , $v_{1} \approx 25.060\,\frac{m}{s}$ and $v_{2} \approx 33.121\,\frac{m}{s}$ , then the work done by the force is:

$W_{F} = \frac{1}{2}\cdot (3.5\,kg)\cdot \left[\left(33.121\,\frac{m}{s} \right)^{2}-\left(25.060\,\frac{m}{s} \right)^{2}\right]$

$W_{F} = 820.745\,J$

The work done by the force is 820.745 joules.

6 0

2 years ago

Which of the following are ways to improve muscle endurance:

Lyrx [107]

How to gain muscular endurance?Combine strength days with cardio days.Reduce your amount of rest between sets.Do fast-paced, high-intensity lifting.Choose compound movements over isolation.10 Ways to Protect Your Joints >>> Remember: Routine is the enemy.Go for hybrid exercises.Add explosive movements to your workout.

4 0

2 years ago

Modern human lifestyle depends on fossil fuels to generate electricity. Predict and explain the long term effect on the environm

Anit [1.1K]

Fossil fuels are non-renewable sources of energy as they are derived from pre-historic fossils and it is certain that they will deplete in the near future. 
The bigegst disadvantage of the fossil fuels is that they release carbon dioxide, nitrogen dioxide, sulfur dioxide, carbon monoxide gasses, which lead to serious environmental issues such as air pollution. They are responsible for the global warming..
Besides the environmental effect, carbon dioxide can also cause serious health complications such as chronic asthma, low lung functioning, chronic bronchitis..

3 0

2 years ago