7) What is the relationship between period and cycles?

A 50 kg runner runs up a flight of stairs. The runner starts out covering 3 steps every second. At the end the runner stops. Thi

nadezda [96]

To solve the problem it is necessary to take into account the concepts of kinematic equations of motion and the work done by a body.

In the case of work, we know that it is defined by,

$W = F * d$

Where,

F= Force

d = Distance

The distance in this case is a composition between number of steps and the height. Then,

$d=h*N$ , for h as the height of each step and N number of steps.

On the other hand we have the speed changes, depending on the displacement and acceleration (omitting time)

$V_f^2-V_i^2 = 2a\Delta X$

Where,

$V_f =$ Final velocity

$V_i =$ Initial Velocity

a = Acceleration

$\Delta X =$ Displacement

PART A) For the particular case of work we know then that,

$W = F*d$

$W = m*g*(h*N)$

$W = 50*9.8*(0.3*30)$

$W = 4.41kJ$

Therefore the Work to do that activity is 4.41kJ

PART B) To find the acceleration (from which we can later find the time) we start from the previously given equation,

$V_f^2-V_i^2 = 2a\Delta X$

Here,

$V_i = \frac{0.3*3}{1} = 0.90m/s\rightarrow$ 3 steps in one second

$v_f = 0$

Replacing,

$V_f^2-V_i^2 = 2a\Delta X$

$0-0.9^2=2a(30*0.3)$

Re-arrange for a,

$a = -\frac{0.9^2}{2*30*0.3}$

$a = -45*10^{-3}m/s^2$

At this point we can calculate the time, which is,

$t = \frac{\Delta V}{a}$

$t = \frac{0-0.9}{-45*10^{-3}}$

$t = 20s$

With time and work we can finally calculate the power

P = \frac{W}{t} = \frac{4.41}{20}

P = 0.2205kW

6 0

3 years ago

Why is tornadoes hitting the east coast of the USA?

OLga [1]

Answer:

The outbreak of tornadoes that tore across the Gulf and the East Coast Tuesday and Wednesday was unusual for two reasons. For one thing, the severe weather encompassed a significant swath of the country. For another, winter is the least likely time for tornadic thunderstorms.

Explanation:

The outbreak of tornadoes that tore across the Gulf and the East Coast Tuesday and Wednesday was unusual for two reasons. For one thing, the severe weather encompassed a significant swath of the country. For another, winter is the least likely time for tornadic thunderstorms.

And yet tornadoes are an expected part of life in the United States—especially in the multi-state area known as Tornado Alley. (Florida, too, sees a disproportionately high number of tornadoes, because of its frequent thunderstorms.) The United States gets more tornadoes, by far, than any other place on the planet. It averages about 1,250 twisters a year. Canada, which sees about 100 tornadoes per year, is a “distant second,” according to the National Centers for Environmental Information.

8 0

3 years ago

What is ozone? How and where is it formed in the atmosphere?

mrs_skeptik [129]

Ozone gas is made up of oxygen molecules that have three atoms. it exists in polluted air and ozone layer. Ozone layer is formed in stratosphere(part of atmosphere).

4 0

3 years ago

An atom’s emission of light with a specific amount of energy confirms that

laila [671]

<span>An atom’s emission of light with a specific amount of energy confirms that </span><span>electrons emit and absorb energy based on their position around the nucleus.

The light emitted from an electron is a result of the electron's quantum jumps/leaps ( atomic electron transitions ) to and from different energy levels.</span>

3 0

3 years ago

Read 2 more answers

What is an independent variable

snow_tiger [21]

Answer:

A variable (often denoted by x ) whose variation does not depend on that of another.

Explanation:

8 0

3 years ago