What is the Earth's magnetic field is known asa. electrosphere
b. biosphere
c. asthenosphere
d. magnetosphere

Answer  

Wind  

Water movement  

A hill

Explanation.  

The question does not specify it is the acceleration of what is to be accelerated. So my answer will be general. Acceleration is the change of velocity with time.  

Wind can cause acceleration of sound. If the sound is travelling in the direction of sound, its speed wound increase. The reverse is also true.  

Water movement can also cause acceleration. When a bout is moving in the direction of water movement, then it will be expected that the resultant speed of the bout to be higher. If the bout was moving against the water movement, its speed would be decreased.  

A hill would reduce the speed of a moving vehicle. This is also an acceleration that is negative (deceleration).  

A stop light and a flat road cannot cause acceleration.  

Answer:

The kinetic energy K of the moving charge is K = 2kQ²/3d = 2Q²/(4πε)3d = Q²/6πεd

Explanation:

The potential energy due to two charges q₁ and q₂ at a distance d from each other is given by U = kq₁q₂/r.

Now, for the two charges q₁ = q₂ = Q separated by a distance d, the initial potential energy is U₁ = kQ²/d. The initial kinetic energy of the system K₁ = 0 since there is no motion of the charges initially. When the moving charge is at a distance of r = 3d, the potential energy of the system is U₂ = kQ²/3d and the kinetic energy is K₂.

From the law of conservation of energy, U₁ + K₁ = U₂ + K₂

So, kQ²/d + 0 = kQ²/3d + K

K₂ = kQ²/d - kQ²/3d = 2kQ²/3d

So, the kinetic energy K₂ of the moving charge is K₂ = 2kQ²/3d = 2Q²/(4πε)3d = Q²/6πεd

Answer:

To calculate how many joules of kinetic energy an electric car can have using the 250 joules of stored chemical energy from the battery, you'll need to consider the efficiency of the energy conversion from chemical to kinetic energy. Electric cars are not 100% efficient in converting stored energy to kinetic energy due to losses in the system, including in the motor, transmission, and drivetrain.

Let's say the efficiency of the conversion is "η," where η is a value between 0 and 1 (e.g., 0.85 for 85% efficiency). The kinetic energy (KE) the car can have will be:

KE = η * 250 joules

You can calculate the kinetic energy for different efficiency values by substituting η into the formula.

For example, if the efficiency is 85%:

KE = 0.85 * 250 joules = 212.5 joules

So, with an 85% efficiency, the electric car can have approximately 212.5 joules of kinetic energy from the 250 joules of stored chemical energy in the battery. The actual efficiency may vary depending on the specific car and its components.

Answer

1.2245 s

Explanation

Using the Newton's law of linear motion,

v = u + gt

where v ⇒ Final velocity

            u ⇒ initial velocity,

             t ⇒ time to reach maximum height.

             g ⇒ acceleration due to gravity.

v = u + at

v = 0 m/s

g = -9.8 m/s²  (negative because the velocity is decreasing)

0 = 6 + -9.8t

9.8t = 6

t = 0.612244898 s

This is the time to reach maximum height. It will take the same time to come back to the hand.

so total time = 0.612244898 × 2

                      = 1.2245 s