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3 years ago

can you help me create a sketch of two different objects with one that has a greater density than the other?

1 answer:

6 0

I don't know how good you are at sketching ... I'm terrible.
But you can put the point across in a dramatic way if you
can sketch a bowling ball and a basketball ... you'll need
to clearly identify them with the markings you sketch on
each ball.

They're the same shape and nearly the same size, but
there's a huge difference in their densities.

You might be interested in

Describe two methods that can be used to cook eggs.

weeeeeb [17]

You can poach an egg which enfolded boiling water and stirring it and dropping a cracked egg in the water until it is fully cooked or you could hard boil and egg by boiling water and letting it cook 5,6 minutes tell you have a soft yellow center or which ever way you prefer

4 0

3 years ago

A 62-kg person jumps from a window to a fire net 20.0 m directly below, which stretches the net 1.4 m. Assume that the net behav

gayaneshka [121]

Answer:

a) x = 0.098

b) x = 2.72 m

Explanation:

(a) To find the stretch of the fire net when the same person is lying in it, you can assume that the net is like a spring with constant spring k. It is necessary to find k.

When the person is falling down he acquires a kinetic energy K, this energy is equal to the elastic potential energy of the net when it is max stretched.

Then, you have:

$K=U\\\\\frac{1}{2}mv^2=\frac{1}{2}kx^2$ (1)

m: mass of the person = 62kg

k: spring constant = ?

v: velocity of the person just when he touches the fire net = ?

x: elongation of the fire net = 1.4 m

Before the calculation of the spring constant, you calculate the final velocity of the person by using the following formula:

$v^2=v_o^2+2gy$

vo: initial velocity = 0 m/s

g: gravitational acceleration = 9.8 m/s^2

y: height from the person jumps = 20.0m

$v=\sqrt{2gy}=\sqrt{2(9.8m/s^2)(20.0m)}=14\frac{m}{s}$

With this value you can find the spring constant k from the equation (1):

$mv^2=kx^2\\\\k=\frac{mv^2}{x^2}=\frac{(62kg)(14m/s)^2}{(1.4m)^2}=6200\frac{N}{m}$

When the person is lying on the fire net the weight of the person is equal to the elastic force of the fire net:

$W=F_e\\\\mg=kx$

you solve the last expression for x:

$x=\frac{mg}{k}=\frac{(62kg)(9.8m/s^2)}{6200N/m}=0.098m$

When the person is lying on the fire net the elongation of the fire net is 0.098m

b) To find how much would the net stretch, If the person jumps from 38 m, you first calculate the final velocity of the person again:

$v=\sqrt{2gy}=\sqrt{2(9.8m/s^2)(38m)}=27.29\frac{m}{s}$

Next, you calculate x from the equation (1):

$x=\sqrt{\frac{mv^2}{k}}=\sqrt{\frac{(62kg)(27.29m/s)^2}{6200N/m}}\\\\x=2.72m$

The net fire is stretched 2.72 m

5 0

3 years ago

Which situation is work not being done? A) A bookcase is slid across carpeting. B) A stack of books is carried at waist level ac

Nastasia [14]

Answer:

B) A stack of books is carried at waist level across a room

Explanation:

Work is defined as:

$W=Fd cos \theta$

where

F is the force applied

d is the displacement of the object

$\theta$ is the angle between the direction of the force and of the displacement

From the formula, we see that the work done is zero when the force and the displacement are perpendicular to each other. Let's now analyze each situation:

A) A bookcase is slid across carpeting. --> work is done, because the force that pushes the bookcase is in the same direction of the displacement

B) A stack of books is carried at waist level across a room. --> no work is done, because the force to carry the book is vertical, while the displacement of the books is horizontal

C) A chair is lifted vertically with respect to the floor. --> work is done, because the force that lifts the chair is vertical, and the displacement is vertical as well

D) A table is dropped onto the ground. --> work is done, because the force of gravity (that makes the table falling down) is vertical and the displacement of the table is also vertical.

5 0

3 years ago

Examine the graph. Select the statement that best describes the energy change in the particles of a substance during melting.

serg [7]

Answer:

B) Absorbed energy results in the change in potential energy.

Explanation:

i got it wrong on usatestpreo

3 0

3 years ago

Read 2 more answers

Automobile A and B are initially 30 m apart travelling in adjacent highway lanes at speeds VA = 14.4 km/hr., VB 23.4 km/hr. at t

marshall27 [118]

Answer:

x = 240 m

Explanation:

This is a kinematics exercise

Let's fix our frame of reference on car A

x = x₀ₐ+ v₀ₐ t + ½ aₐ t²

the initial position of car a is zero

x = 0 + v₀ₐ t + ½ 0.8 t²

for car B

x = x_{ob} + v_{ob} t - ½ a_b t²

car B's starting position is 30 m

x = 30 + v_{ob} t - ½ 0.4 t²

at the point where they meet, the position of the two vehicles is the same

0 + v₀ₐ t + ½ 0.8 t² = 30 + v_{ob} t - ½ 0.4 t²

let's reduce the speeds to the SI system

v₀ₐ = 14.4 km / h (1000 m / 1 km) (1h / 3600s) = 4 m / s

v_{ob} = 23.4 km / h = 6.5 m / s

4 t + 0.4 t² = 30 + 6.5 t - 0.2 t²

0.2 t² - 2.5 t - 30 = 0

t² - 12.5 t - 150 = 0

we solve the quadratic equation

t = $\frac{12.5 \pm \sqrt{12.5^2 + 4 \ 150} }{2}$

t = $\frac{12.5 \ \pm 27.5}{2}$

t₁ = 20 s

t₂ = -7.5 s

time must be a positive quantity so the correct result is t = 20 s

let's look for the distance

x = 4 t + ½ 0.8 t²

x = 4 20 + ½ 0.8 20²

x = 240 m

8 0

3 years ago