What is the acceleration of a ball traveling horizontally with an initial velocity of 20 meters/second and, 2.0 seconds later, a velocity of 30 meters/second?

Answer:

Energy of photon,

Explanation:

It is given that,

Wavelength of photon,

It strikes a mercury atom in the ground state. We have to find the energy of this photon. It can be calculated using below relation as :

Where

h is the Planck's  constant

c is the speed of light

So,

Hence, the above value is the energy of this photon.

The answer would be:

A. Longer wires have less resistance.

Here is why:

The statement is false because longer wires tend to have greater resistance. Look at the formula of resistance below:

ρ = resistivity

L = length

A = cross-sectional area

As you can see Length of the wire is directly proportional to the resistance, which means as the Length increases, the Resistance increases.

Answer:

A. Longer wires have less resistance.

Explanation:

Answer:

The volume of the object = 0.0203 m³

Explanation:

From Archimedes principle,

Upthrust = lost in weight = amount of water displaced.

U = W₁ - W₂

Where U = upthrust, W₁ = Weight in air, W₂ = weight in water.

U = 930- 731

U = 199 N.

but mass of water displaced,

m = U/g where g = 9.8 m/s²

m = 199/9.8

m = 20.31 kg.

Recall,

Density = mass/volume.

Density of water = mass of water displaced/ volume of water displaced

D = m/V

V = m/D......................................... Equation 1

Where V = volume of water displaced, m = 20.31 kg, D = 1000 kg/m³

Substitute into equation 1

V = 20.31/1000

V = 0.0203 m³

the volume of water displaced = 0.0203 m³

Note: That when an object is immersed in water, the volume of water it displaced is equal to it's volume.

Hence, Volume of water displaced = volume of the object.

Hence the volume of the object = 0.0203 m³

Answer:

    v = R w    

With this expression we see that for each point at different radius the tangential velocity is different

Explanation:

They indicate that the angular velocity is constant, that is

            w = dθ / dt

Where θ is the radius swept angle and t the time taken.

The tangential velocity is linear or

           v = dx / dt

Where x is the distance traveled in time (t)

In the definition of radians

          θ = s / R

Where s is the arc traveled and R the radius vector from the pivot point, if the angle is small the arc (s) and the length (x) are almost equal

         θ = x / R

We substitute in the speed equation

         v = d (θ R) / dt

The radius is a constant for each point

         v = R dθ / dt

         v = R w

With this expression we see that for each point at different radius the tangential velocity is different