A ball rolls at a speed of 6cm/s how far does the ball roll in 40 seconds ? ___

based on the law of conservation of energy. how can we reasonably improve a machines ability to do work? A.move the machine to a

natima [27]

The correct answer is

C. reduce the friction between its moving parts

In fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

8 0

4 years ago

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A truck traveling down the highway collides with a slower moving mosquito traveling in the same direction. Which of the followin

Ipatiy [6.2K]

Answer:

B. The truck and mosquito exert the same size force on each other.

Explanation:

Newton's third law (law of action-reaction) states that

"When an object A exerts a force (action) on an object B, then object B exerts an equal and opposite force (reaction) on object A"

In this case, we can call

object A = the truck

object B = the mosquito

Thereforce according to Newton's third law, the force exerted by the truck on the mosquito is equal in magnitude to the force exerted by the mosquito on the truck (and in opposite direction).

The reason for which the mosquito will experience much more damage is the fact that the mosquito's mass is much smaller than the truck's mass, and since the acceleration is inversely proportional to the mass:

$a=\frac{F}{m}$

the mosquito will experience a much larger deceleration than the truck, therefore much more damage.

6 0

3 years ago

Suppose a woman raises a 65 N object in 2m in 4 seconds.

Novosadov [1.4K]

Answer:

$\huge\boxed{\sf P.E = 130\ Joules}$

$\huge\boxed{\sf P = 32.5\ Watts}$

Explanation:

<u>Given Data:</u>

Weight = W = 65 N

Height = h = 2 m

Time = t = 4 secs

<u>Required:</u>

Power = P = ?

Work Done in the form of Potential Energy = P.E. = ?

<u>Formula:</u>

P.E. = Wh

P = P.E. / t

<u>Solution:</u>

P.E. = (65)(2)

P.E = 130 Joules

P = P.E. / t

P = 130 / 4

P = 32.5 Watts

$\rule[225]{225}{2}$

Hope this helped!

8 0

3 years ago

How can we describe, model, and explain the material world, and are there limitations?

taurus [48]

Answer:· A model is a description of natural phenomenon that scientists can use to make predictions. A good model is both as accurate as possible and as simple as possible, which makes it not only powerful but also easy to understand. However, no matter how good they are, models will almost always have limitations.

Explanation:

5 0

3 years ago

Sheila eats an energy bar right before she goes on a run. What energy changes will occur in sheila as she runs after eating?

LiRa [457]

The energy bar eaten by Sheila has chemical energy locked up inside it. This chemical energy is converted to mechanical energy in form of potential and kinetic energy and this in turn is converted to heat energy as the run progresses. Thus, the energy changes are: chemical energy to mechanical energy [kinetic and potential] and finally to heat energy.

8 0

3 years ago

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A ball rolls at a speed of 6cm/s how far does the ball roll in 40 seconds ? ____cm