How can we find velocity?*

In the Biomedical and Physical Sciences building at MSU there are 135 steps from the ground floor to the sixth floor. Each step

Kipish [7]

Answer:

W = 16.4 kJ

Explanation:

Given that,

There are 135 steps from the ground floor to the sixth floor.

Each step is 16.6 cm tall.

The mass of a person, m = 73.5 kg

We need to find the work done by the person. We know that,

Work done = Fd

Where

d is the displacement, d = 135 × 0.166 = 22.41

So,

W = 73.5 × 10 × 22.41

= 16471.35 J

or

W = 16.4 kJ

So, 16.4 kJ is the work done by the person.

3 0

2 years ago

g A ping pong ball (thin shell sphere) rolls down an incline at 30° from rest. What is its acceleration

Aleonysh [2.5K]

Answer:

Explanation:

According to newtons second law of motion;

F = ma .... 1

Also the force acting aong the inclines is expressed as;

F = mgsintheta

m is the mass of the object

a is the acceleration

theta is angle of inclination

Equate 1 and 2

ma = mg sin theta

a = gsin(theta)

a = 9.8sin30

a = 9.8(0.5)

a = 4.9m/s²

Hence the acceleration of the ping pong is 4.9m/s²

3 0

2 years ago

If a non-human civilization were to develop on Saturn's largest moon, Titan, its scientists might well develop a temperature sca

klasskru [66]

Answer: $-330.47 \°M$

Explanation:

Let's begin by explaining that the relation between the Celsius scale and Kelvin scale is:

$\°C +273.15=K$

This means the absolute zero point of the Kelvin scale is $0 K=-273.15 \°C$

Keeping this in mind, we have the freezing point and boling point of Methane as:

Freezing point: $0 \°M=-182.6 \°C=90.55 K$

Boiling point: $100 \°M=-155.2 \°C=117.95 K$

According to this, there is a linear relation between the methane scale ( $\°M$ ) and the Kelvin scale in the form:

$T=a+bt_{M}$ (1)

Where:

$T$ is the temperature in Kelvin

$t_{M}$ is the temperature in degrees Methane

Firstly, we need to find the value of $a$ and $b$ with the two given points ( $90.55 K$ and $117.95 K$ ):

When $T=90.55$ and $t_{M}=0$ :

$90.55=a+b(0)$

$a=90.55$ (2)

When $T=117.95$ and $t_{M}=100$ :

$117.95=90.55+b(100)$

$b=0.274$ (3)

Now we have the linear equation:

$T=90.55+0.274t_{M}$ (4)

Isolating $t_{M}$ :

$t_{M}=\frac{T-90.55}{0.274}$ (5)

Evaluating for $T=0 K$ :

$t_{M}=\frac{0-90.55}{0.274}$ (6)

Finally:

$t_{M}=-330.47 \°M$

This means $0 K=-330.47 \°M$

7 0

2 years ago

A stone is dropped from the upper observation deck of a tower, 250 m above the ground. (Assume g = 9.8 m/s2.) (a) Find the dista

Vitek1552 [10]

(a) $y(t)=250 - 4.9 t^2$

For an object in free-fall, the vertical position at time t is given by:

$y(t) = h + ut - \frac{1}{2}gt^2$

where

h is the initial vertical position

u is the initial vertical velocity

g = 9.8 m/s^2 is the acceleration of gravity

t is the time

In this problem,

h = 250 m

u = 0 (the stone starts from rest)

So, the vertical position of the stone is given by

$y(t) = 250 - \frac{1}{2}(9.8) t^2 = 250 - 4.9 t^2$

(b) 7.14 s

The time it takes for the stone to reach the ground is the time t at which the vertical position of the stone becomes zero:

y(t) = 0

Which means

$y(t) = h - \frac{1}{2}gt^2=0$

So for the stone in the problem, we have

$250 - 4.9 t^2 = 0$

Solving for t, we find:

$t=\sqrt{\frac{250}{4.9}}=7.14 s$

(c) -70.0 m/s (downward)

The velocity of an object in free fall is given by the equation

$v(t) = u - gt$

where

u is the initial velocity

g = 9.8 m/s^2 is the acceleration of gravity

t is the time

Here we have

u = 0

So if we substitute t = 7.14 s, we find the velocity of the stone at the time it reaches the ground:

$v=0-(9.8 m/s^2)(7.14 s)=-70.0 m/s$

The negative sign means the direction of the velocity is downward.

(d) 6.94 s

In this situation, the stone is thrown downward with an initial speed of 2 m/s, so its initial velocity is

u = -2 m/s

So the equation of the vertical position of the stone in this case is

$y(t) = h + ut - \frac{1}{2}gt^2=250 - 2t - 4.9 t^2$

By solving the equation, we find the time t at which the stone reaches the ground.

We find two solutions:

t = -7.35 s

t = 6.94 s

The first solution is negative, so it has no physical meaning, therefore we discard it. So, the time it takes for the stone to reach the ground is:

t = 6.94 s

6 0

2 years ago

A student weighs a sample of an unkown metal and finds the mass to be 39.27g what is the metal?

xxTIMURxx [149]

The unknown metal with a mass of 39.27 g is potassium with the symbol K.

The mass of an atom is due to protons and neutrons present in it.

The protons and neutrons are together present in the nucleus of an atom.

The mass of any element is given by its mass number whose formula is

Mass Number = Number of protons + Number of neutrons

In the given case 39 = Number of protons + Number of neutrons

The only element of the periodic table which satisfies the above equation is potassium because it has 19 protons and 20 neutrons.

Thus, the unknown metal with a mass of 39.27 g is potassium with the symbol K.

To know more about "mass number", refer to the following link:

brainly.com/question/4408975?referrer=searchResults

#SPJ4

7 0

1 year ago