All categories

3 years ago

A car skids to a stop. What happens to its kinetic energy?

Physics

1 answer:

Orlov [11]3 years ago

4 0

Answer:

a) it turns into thermal energy

Explanation:

Due to the law of energy conservation, an object cannot just "lose" its kinetic energy, it must become another type of energy.

This eliminates option b. because energy of any type cannot disappear.

About option c, we have that the kinetic energy becomes potential energy, but the potential energy of an object is due to its height above the ground, so we cannot have potential energy if the tires are on the floor, we discard option c.

Also, kinetic energy is the energy an object has due to its motion, this means that if the object is not moving, it cannot have kinetic energy.

This eliminates option d.

The correct option is a) it turns into thermal energy.

The option meets the characteristic that the kinetic energy does not disappear, it is transformed into another type of energy. In this case it is thermal energy or heat, generated by friction between the tires and the floor.

You might be interested in

How many watt hours will 3-155amp hour 12 volt batteries wired in a parallel configuration produce?

Ede4ka [16]

Answer:

B 5580 W•hr

Explanation:

A Watt is a Volt times an Amp

3(12 V(155 A•hr)) = 5580 W•hr

4 0

3 years ago

The histogram below shows the number of downloads of a song over time.

Allisa [31]

Given data:

It is a graphical display where the data is grouped in to ranges

A diagram consists rectangles, whose area is proportional to frequency of a variable and whose width is equal to the class interval.

It is an accurate representation of the distribution of numerical data.

<em>From Figure:</em>

Each box in the graph (small rectangle box) is assumed to be one download. So, in the graph the time between 8 p.m to 9 p.m, the number of downloads are 8.75 approximately (because the last box is incomplete, therefore 8 complete boxes and 9th is more than half).

<em>So, We conclude that the total number of downloads are approximately 9 in the time span of 8 p.m. to 9 p.m.</em>

7 0

3 years ago

7. Two people are pushing a 40.0kg table across the floor. Person 1 pushes with a force of 490N

artcher [175]

Answer:

20.4 $m/s^{2}$

Explanation:

To start doing this problem, first draw a free body diagram of the table. My teacher always tells us to do this, and I find that it is very helpful. I have attached a free body diagram to this answer- take a look at it.

First, let us see if Net force = MA. To do that, we need to determine whether the object is at equilibrium horizontally. For an object to be at equilibrium, it either needs to be moving at a constant velocity or not moving at all. Also, if an object is at equilibrium, there will not be any acceleration. But we know that there IS acceleration horizontally, so it cannot be in equilibrium. If it is not in equilibrium, we can use the formula ∑F= ma.

Let us determine the net force. Since the object is moving horizontally, we can ignore the weight and normal force, because they are vertical forces. The only horizontal forces we need to worry about are the applied force and force of friction.

Applied force = 1055 N (490 + 565)

Friction force= Unknown

To find the friction force, use the kinetic friction formula, Friction = μkN

μk is the coefficient, which the problem includes- it is 0.613.

N is the normal force, which we have to find.

*To find the normal force, we have to determine if the object is at equilibrium VERTICALLY. Since it has no acceleration vertically (it's not moving up/down), it is at equilibrium. Now, when an object is at equilibrium in one direction, it means that all the forces in that direction are equal. What are our vertical forces? Weight (mg) and Normal force (N). So it means that the Normal force is equal to the Weight.

Weight = mg = (40)(9.8) = 392 N

Normal force = 392 N

Now, plug it back into the formula (μkN): (0.613)(392) = 240.296 N

Friction = 240.296 N

Now that we know the friction, we can find the horizontal net force. Just subtract the friction force, 240.296 from the applied force, 1055 N

Horizontal Net Force: 814.704 N

Now that we know the net force, plug in the numbers for the formula

∑F= ma.

814.704 = (40.0)(a)

*Divide on both sides)

a = 20.3676 m/s^2

Round it to 3 significant figures, to get:

20.4 $m/s^{2}$

7 0

3 years ago

How much potintial energy is in a closed system where the height of the object is 2 m, and the mass is 10 kg?

Lorico [155]

Answer:

D. 196 J

Explanation:

PE=mgh=10×9.8×2=196J

6 0

3 years ago

Read 2 more answers

What does vitamin c do for our body?

Ksju [112]

Answer:

necessary for the growth, development and repair of all body tissues. it's involved in many body functions, including formation of collagen, absorption of iron, the proper functioning of the immune system, wound healing, and the maintenance of cartilage, bones, and teeth.

Explanation:

6 0

3 years ago

Read 2 more answers