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2 years ago

8

Which of these actions requires KINETIC Energy? Choose all of the correct answers.

2 answers:

Keith_Richards [23]2 years ago

8 0

Answer:

turning a doorknob

Explanation:

it will snap back once you release it.

Harman [31]2 years ago

7 0

Answer:

- Turning a doorknob

- Swimming

- Hitting a tennis ball

Explanation:

Kinetic energy is the form of energy that an object or a particle has due to its motion (horizontal or vertical). An object gains kinetic energy when work is performed on it by putting a net force. This makes the object to speed up and acquire kinetic energy. Any object or particle that is moving is using kinetic energy

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Approximately how many degrees does high latitude ocean water change from the ocean surface to a depth of 1 km

saveliy_v [14]

There is no change in ocean water temperature when it is from the ocean surface to a depth of 1 km.

3 0

3 years ago

The voltage ???? in a simple electrical circuit is slowly decreasing as the battery wears out. The resistance ???? is slowly inc

zimovet [89]

Answer:

The change in current at $R =456 \Omega$ is $\frac{dI}{dt} = 7.032 * 10^{-5} A/s$

Explanation:

From the question we are told that

The resistance is $R = 465 \Omega$

The current is $I = 0.09A$

The change in voltage with respect to time is $\frac{dV}{dt} = - 0.03 V/s$

The change in resistance with time is $\frac{dR}{dt} = 0.03 \Omega /s$

According to ohm's law

$V = IR$

differentiating with respect to time using chain rule

$\frac{dV}{dt} = I \frac{dR}{dt} + R * \frac{dI}{dt}$

substituting value at R = 456

$-0.0327 = 0.09 * 0.03 + 456* \frac{dI}{dt}$

$\frac{dI}{dt} = 7.032 * 10^{-5} A/s$

6 0

3 years ago

An elevator is moving downward when someone presses the emergency stop button. The elevator comes to rest a short time later. Gi

Oksanka [162]

Answer:

Velocity: +ve, Acceleration: -ve

Explanation:

Here I've considered downward direction as positive direction.

6 0

3 years ago

Read 2 more answers

Three equal point charges, each with charge 1.05 μCμC , are placed at the vertices of an equilateral triangle whose sides are of

kirza4 [7]

Answer:

The value is $U = 0.06 \ J$

Explanation:

From the question we are told that

The value of charge on each three point charge is

$q_1 = q_2 = q_3 =q= 1.05 \mu C = 1.05 *10^{-6} \ C$

The length of the sides of the equilateral triangle is $r = 0.500 \$

Generally the total potential energy is mathematically represented as

$U = k * [ \frac{q_1 * q_2}{r} + \frac{q_2 * q_3}{r} + \frac{q_3 * q_1}{r} ]$

=> $U = k * 3 * \frac{q^2}{r}$

Here k is coulomb constant with value $k = 9*10^{9}\ kg\cdot m^3\cdot s^{-4} \cdot A^{-2}.$

=> $U = 9*10^9 * 3 * \frac{(1.05 *10^{-6})^2}{0.5 }$

$U = 0.06 \ J$

6 0

3 years ago

A ball rolling down a hill was displaced 21.9 m while uniformly accelerating from rest. If the final velocity was 7.14 m/s, what

belka [17]

Answer:

a = 1.16 m/s²

Explanation:

In order to find the acceleration of the ball we will use 3rd equation of motion.

2as = Vf² - Vi²

where,

a = acceleration = ?

s = displacement = 21.9 m

Vf = Final Velocity = 7.14 m/s

Vi = Initial Velocity = 0 m/s (Since, ball starts from rest)

Therefore, using the values, we get:

2a(21.9 m) = (7.14 m/s)² - (0 m/s)²

a = (50.97 m²/s²)/(43.8 m)

<u>a = 1.16 m/s²</u>

4 0

3 years ago