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2 years ago

Please help!! For a science quiz

Physics

1 answer:

klio [65]2 years ago

4 0

1.Velocity (v) is a vector quantity that measures displacement (or change in position, Δs) over the change in time (Δt), represented by the equation v = Δs/Δt. Speed (or rate, r) is a scalar quantity that measures the distance traveled (d) over the change in time (Δt), represented by the equation r = d/Δt.

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Sitting in a chairlift, Rebecca has a gravitational potential energy of 5,997.6

stira [4]

Answer:

B) 12 m

Explanation:

Gravitational potential energy is:

PE = mgh

Given PE = 5997.6 J, and m = 51 kg:

5997.6 J = (51 kg) (9.8 m/s²) h

h = 12 m

8 0

2 years ago

A felt-covered beanbag is fired into a empty wooden crate that sits on a concrete floor and is open on one side. The beanba

Phantasy [73]

Answer:

31.42383 m/s

Explanation:

g = Acceleration due to gravity = 9.81 m/s²

$\mu$ = Coefficient of kinetic friction = 0.48

s = Displacement = 0.935 m

$m_1$ = Mass of bean bag = 0.354 kg

$m_2$ = Mass of empty crate = 3.77 kg

$v_1$ = Speed of the bean bag

$v_2$ = Speed of the crate

Acceleration

$a=-\frac{f}{m}\\\Rightarrow a=-\frac{\mu mg}{m}\\\Rightarrow a=-\mu g$

$a=--9.81\times 0.48=4.7088\ m/s^2$

From equation of motion

$v^2-u^2=2as\\\Rightarrow v=\sqrt{2as+u^2}\\\Rightarrow v=\sqrt{2\times 4.7088\times 0.935+0^2}\\\Rightarrow v=2.96739\ m/s$

In this system the momentum is conserved

$m_1v_1=(m_1+m_2)v_2\\\Rightarrow v_1=\frac{(m_1+m_2)v_2}{m_1}\\\Rightarrow u=\frac{(0.354+3.77)\times 2.69739}{0.354}\\\Rightarrow u=31.42383\ m/s$

The speed of the bean bag is 31.42383 m/s

8 0

3 years ago

Two uniform solid cylinders, each rotating about its central (longitudinal) axis, have the same mass of 3.56 kg and rotate with

Natali5045456 [20]

Answer:

(a) 3107.98 J

(b) 14530.6 J

Explanation:

mass, m = 3.56 kg

angular speed, ω = 179 rad/s

Moment of inertia of solid cylinder, I = 1/2 mr^2

where, m is the mass and r be the radius of the cylinder.

(a) radius, r = 0.330 m

I = 0.5 x 3.56 x 0.330 x 0.330 = 0.194 kgm^2

The formula for the rotational kinetic energy is given by

$K = \frac{1}{2}I\omega ^{2}$

K = 0.5 x 0.194 x 179 x 179 = 3107.98 J

(b) radius, r = 0.714 m

I = 0.5 x 3.56 x 0.714 x 0.714 = 0.907 kgm^2

The formula for the rotational kinetic energy is given by

$K = \frac{1}{2}I\omega ^{2}$

K = 0.5 x 0.907 x 179 x 179 = 14530.6 J

3 0

2 years ago

If the mass of both weights is 225 gm, the first mass is located 20∘ north of east, the second mass is located 20∘ south of east

Montano1993 [528]

Answer:

The voltage is 2.114 V.

Explanation:

Given that,

Mass of both weights = 225 gm

Transducer sensitivity = 0.5 V/N

The first mass is located 20∘ north of east, the second mass is located 20∘ south of east,

We need to calculate the net equivalent force

Using formula of force

$F_{3}=m_{1}g\cos\theta+m_{2}g\cos\theta$

$F_{3}=2mg\cos\theta$

Put the value into the formula

$F_{3}=2\times0.225\times10\cos20^{\circ}$

$F_{3}=4.228\ N$

We need to calculate the voltage

Using formula of voltage

$Voltage =sensitivity\times F_{3}$

Put the value into the formula

$Voltage=0.5\times4.228$

$Voltage =2.114\ V$

Hence, The voltage is 2.114 V.

7 0

3 years ago

The deviation of a value (x) from the mean of the sample divided by the standard deviation (s)of the sample is known as the "z"

Ugo [173]

Answer:

true.

Explanation:

z-score gives an idea of how far the value of data is from the mean point. Basically is the measure of a standard deviation below or above the mean.

More the deviation of the data from the mean more is the standard deviation.

Z-score or value is calculated by the expression given below:

$z = \dfrac{x-\mu}{\sigma}$

x is the value

μ is the mean

σ is the standard deviation

Hence, the statement given is true.

6 0

2 years ago