The wavelength of a pendulum on a string is 3.5 meters and its speed is 4.5 m/s. What is its frequency?

The frequency is 1.286 Hz

Explanation:

Frequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz). That is, the frequency is a magnitude that measures the number of repetitions that an event can have per unit of time.

Wavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. it is expressed in units of length (m).

The propagation speed (v) is the speed with which the wave propagates in the medium.

These three variables are related by the following equation:

v = f * λ

where the speed is v the wavelength is λ and the frequency is f.

So the frequency can be calculated by:

In this case:

Replacing:

Solving:

f=1.286

f=1.286 Hz

The frequency is 1.286 Hz

when 25.0 ml of 0.700 mol/l naoh was mixed in a calorimeter with 25.0 ml of 0.700 mol/l hcl, both initially at 20.0 °c, the temperature increased to 22.1 °c. the heat capacity of the calorimeter is 279 j/°c.

the equation for the reaction is:

naoh + hcl → nacl + h₂o

moles of hcl = 0.0250 l hcl ×

0.700

mol hcl

1 l hcl = 0.0175 mol hcl

volume of solution = (25.0 + 25.0) ml = 50.0 ml

mass of solution = 50.0 ml soln ×

1.00

ml soln

= 50.0 g soln

δt=t2-t1

= (22.1 – 20.0) °c = 2.1 °c

the heats involved are

heat from neutralization + heat to warm solution + heat to warm calorimeter = 0

q1+q2+q3=0

nδh+mcδt+cδt=0

0.0175 mol ×

δh

+ 50.0 g × 4.184 j·g⁻¹°c⁻¹ × 2.1 °c + 279 j°c⁻¹ × 2.1 °c = 0

0.0175 mol ×

δh

+ 439.32 j + 585.9 j = 0

0.0175 mol ×

δh

= -1025.22 j

δh=1025.22j0.0175 mol= -58 600 j/mol = -58.6 kj/mol

cytokinesis is the splitting of a cell membrane to form 2 identical daughter cells. it's similar to mitosis as both cells have identical copies of dna and cytokinesis is a step in the mitotic cycle.