Which of the answers shows three examples of a physical change

How does increasing the distance between charged objects affect the electric force between them?

mina [271]

Answer: energy force

Explanation:

6 0

3 years ago

W is the work done on the system, and K, U, and Eth are the kinetic, potential, and thermal energies of the system, respectively

MArishka [77]

Answer:

1) a block going down a slope

2) a) W = ΔU + ΔK + ΔE, b) W = ΔE, c) W = ΔK, d) ΔU = ΔK

Explanation:

In this exercise you are asked to give an example of various types of systems

1) a system where work is transformed into internal energy is a system with friction, for example a block going down a slope in this case work is done during the descent, which is transformed in part kinetic energy, in part power energy and partly internal energy that is represented by an increase in the temperature of the block.

2)

a) rolling a ball uphill

In this case we have an increase in potential energy, if there is a change in speed, the kinetic energy also increases, if the change in speed is zero, there is no change in kinetic energy and there is a change in internal energy due to the stationary rec in the point of contact

W = ΔU + ΔK + ΔE

b) in this system work is transformed into internal energy

W = ΔE

c) There is no friction here, therefore the work is transformed into kinetic energy

W = ΔK

d) if you assume that there is no friction with the air, the potential energy is transformed into kinetic energy

ΔU = ΔK

7 0

3 years ago

A small toy car travels 2.0 meters in 120 seconds. what is the speed of the car?

mamaluj [8]

Answer: $\dfrac{1}{60} ms^{-1}$

Explanation:

Speed of an object is defined as the ratio of the distance covered by the object to the time taken to cover that distance.

Let $s$ be the speed of the object.

Let $D$ be the distance travelled by the object.

Let $t$ be the time taken by the object.

So, $s=\frac{D}{t}$

s= $\frac{2}{120}=\frac{1}{60}ms^{-1}$

So,the speed of the car is $\frac{1}{60}ms^{-1}$

4 0

3 years ago

2. Kevin works as a janitor, and he is pushing a fully-

dybincka [34]

The time taken for him to move the bin 6.5 m is 2.30 s.

The given parameters;

weight of the load, w = 557 N
force applied , F = 410 N
angle of force, = 15°
coefficient of kinetic friction = 0.46
distance moved, d = 6.5 m

The net horizontal force on the recycling bin is calculated as follows;

$Fcos\theta - F_k = ma$

where;

m is the mass of the recycling bin
$F_k$ is the frictional force

W = mg

$557 = 9.8m\\\\m = \frac{557}{9.8} \\\\m = 56.84 \ kg$

The net horizontal force on the recycling bin is calculated as;

$Fcos \theta - F_k = ma\\\\Fcos\theta - \mu_kF_n = ma\\\\410\times cos(15) \ - \ 0.46(557) = 56.84 a\\\\139.8 = 56.84a\\\\a = \frac{139.8}{56.84} \\\\a = 2.46 \ m/s^2$

The time taken for him to move the bin 6.5 m is calculated as follows;

$s = v_0t + \frac{1}{2} at^2\\\\6.5 = 0 + \frac{1}{2} \times 2.46\times t^2\\\\6.5 = 1.23 t^2\\\\t^2 = \frac{6.5 }{1.23} \\\\t^2 = 5.285\\\\t = \sqrt{5.285} \\\\t = 2.30 \ s$

Thus, the time taken for him to move the bin 6.5 m is 2.30 s.

Learn more here:brainly.com/question/21684583

7 0

2 years ago

Alkaline batteries have the advantage of putting out constant voltage until very nearly the end of their life. How long will an

Sidana [21]

Answer:

Explanation:

Voltage, V = 1.58 V

Power, P = 1 W

1 A.h

Charge, Q = 1 A.h = 1 x 3600 A.s = 3600 C

Power x time = Voltage x charge

1 x t = 1.58 x 3600

t = 1.58 x 3600 second

t = 1.58 hours

8 0

3 years ago