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3 years ago

A 10.0-kg animal is running at a rate of 3.0 m/s. What is the kinetic energy of the animal?

1 answer:

4 0

Kinetic energy is calculated by using formula:

Ek = 1/2*m*v^2

Now we replace values of mass and speed in this formula.

Ek = 1/2*10*3^2 = 45.0J

When you have a formula and all variable values are given in the text of question just replace variable values in equation and find the final value.

You might be interested in

Which one of the following si units is used to measure current?

kondaur [170]

The unit of electric current is the 'ampere'.

That's the current in the circuit when one coulomb of charge
flows past any fixed point every second.

6 0

3 years ago

An object is 16.0cm to the left of a lens. The lens forms an image 36.0cm to the right of the lens.

CaHeK987 [17]

A) 11.1 cm

We can find the focal length of the lens by using the lens equation:

$\frac{1}{f}=\frac{1}{p}+\frac{1}{q}$

where

f is the focal length

p = 16.0 cm is the distance of the object from the lens

q = 36.0 cm is the distance of the image from the lens (taken with positive sign since it is on the opposide side to the image, so it is a real image)

Solving the equation for f:

$\frac{1}{f}=\frac{1}{16.0 cm}+\frac{1}{36.0 cm}=0.09 cm^{-1}\\f=\frac{1}{0.09 cm^{-1}}=11.1 cm$

B) Converging

The focal length is:

- Positive for a converging lens

- Negative for a diverging lens

In this case, the focal length is positive, so it is a converging lens.

C) 18.0 mm

The magnification equation states that:

$\frac{h_i}{h_o}=-\frac{q}{p}$

where

$h_i$ is the heigth of the image

$h_o$ is the height of the object

$q=36.0 cm$

$p=16.0 cm$

Solving the formula for $h_i$ , we find

$h_i = -h_o \frac{q}{p}=-(8.00 mm)\frac{36.0 cm}{16.0 cm}=-18.0 mm$

So the image is 18 mm high.

D) Inverted

From the magnification equation we have that:

- When the sign of $h_i$ is positive, the image is erect

- When the sign of $h_i$ is negative, the image is inverted

In this case, $h_i$ is negative, so the image is inverted.

4 0

3 years ago

A paintball is shot horizontally in the positive x direction at time t after the ball is shot it is 4 cm to the right and 4 cm b

Artist 52 [7]

<u>Answer:</u>

At time 2t the paint ball is at 8 cm to the right and 16 cm to the bottom

<u>Explanation:</u>

We have equation of motion , $s= ut+\frac{1}{2} at^2$ , s is the displacement, u is the initial velocity, a is the acceleration and t is the time.

Considering the horizontal motion of paint ball

Distance traveled during time t = 4 cm

Initial velocity = u m/s

Acceleration = 0 $m/s^2$

So $4 = u*t+\frac{1}{2} *0*t^2\\ \\ u = \frac{4}{t}$

Now at time 2t,

$S= u*2t+\frac{1}{2} *0*(2t)^2\\ \\=\frac{4}{t} *2t\\ \\ =8cm$

So horizontal distance traveled in time 2t = 8 cm to the right

Now considering the vertical motion of paint ball

Distance traveled during time t = 4 cm

Initial velocity = 0 m/s

Acceleration = -g $m/s^2$

$4=0*t-\frac{1}{2} *g*t^2\\ \\ t^2=\frac{-8}{g}$

At time 2t,

$S=0*2t-\frac{1}{2} *g*(2t)^2\\ \\ =-\frac{1}{2} *g*4*\frac{-8}{g}\\ \\ =16 cm$

So vertical distance traveled in time 2t = 16 cm to the bottom

6 0

3 years ago

Discuss how planck's hypothesis explain the observed blackbody spectrum.

Rashid [163]

Answer:

Planck's radiation law, a mathematical relationship formulated in 1900 by German physicist Max Planck to explain the spectral-energy distribution of radiation emitted by a blackbody (a hypothetical body that completely absorbs all radiant energy falling upon it, reaches some equilibrium temperature, and then reemits

Explanation:

6 0

2 years ago

A professor sits on a rotating stool that is spinning at 10.0 rpm while she holds a heavy weight in each of her hands. Her outst

kykrilka [37]

Answer:

r = 0.491 m

Explanation:

In this case the System is formed by the teacher with the two masses, so the forces during movement are internal and the angular momentum is conserved

Initial.

L₀ = I₀ w₀

Final

Lf = I w

L₀ = Lf

I₀ w₀ = I w

The moment of inertia is

I₀ = m r₀²

I = m r²

Let's replace

m r₀² w₀ = m r² w

r² = r₀² w₀ / w

Angular velocity

w₀ = 10 rpm (2pi rad / 1 rev) (1 min / 60 s) = 1.047 rad / s

w = 32.5 rpm = 3.403 rad / s

Let's calculate

r = √(0.785 1.047 / 3.403)

r = 0.491 m

5 0

3 years ago