1. With the exception to water, matter (expands, contracts) when it gets

You place a large pebble in a slingshot, pull the elastic band back to your chin, and release it, launching the pebble horizonta

sladkih [1.3K]

Answer:

The larger pebble has 25 times more mass.

Explanation:

To solve the exercise it is necessary to apply the work and energy conservation equations.

For the case described, the work done must be preserved and must be the same, that is,

$W = 0$

By definition work linked to the conservation of kinetic energy would be given by

$\Delta KE = W = 0$

$\Delta KE = 0$

$KE_{larger}-KE_{smaller} = 0$

$KE_{larger}=KE_{smaller}$

$\frac{1}{2}m_lv_l^2 = \frac{1}{2}m_sv_s^2$

$m_lv_l^2 = m_sv_s^2$

The ratio between the mass and the velocity would be,

$\frac{m_l}{m_s}=\frac{v_s^2}{v_l^2}$

$\frac{m_l}{m_s} = \frac{500^2}{100^2}$

$\frac{m_l}{m_s} = 25$

Therefore the answer is: The larger pebble has 25 times more mass.

4 0

3 years ago

A worker pushes a box across the floor to the right at a constant speed with a force of 25N. What

icang [17]

Answer:

Friction between the box and the floor is 25N to the left

Explanation:

There are two forces acting on the box along the horizontal direction:

- The force of push applied by the worker, in the forward direction, F

- The force of friction, $F_f$ , acting in the opposite direction (backward)

So the net force acting on the box is

$F_{net}=F-F_f$

According to Newton's second law of motion, the net force on an object is equal to the product between its mass (m) and its acceleration (a), so we can write:

$F_{net}=ma$

And so

$F-F_f = ma$

However, in this case the box is moving at constant speed; this means that its acceleration is zero:

$a=0$

Therefore we have:

$F-F_f=0$

Which means

$F_f=F$

And since we are told that

$F=25 N$

This means that the force of friction is also 25 N:

$F_f=F=25 N$

6 0

4 years ago

Read 2 more answers

An a.c. supply is connected to a wire stretched between the poles of a magnet. Which way does the wire move?

snow_lady [41]

The wire vibrates back and forth between the poles of the magnet.
The frequency of the vibration is the frequency of the AC supply.

7 0

2 years ago

Why am i getting so many spam calls on my cell phone.

OleMash [197]

Answer:

Why do I keep getting spam calls? Experts credit the ascendance of spam phone calls to fundamental problems with caller ID, a phone system where anyone can operate as a carrier, the inability to detect bad callers, and a number of bad actors exploiting those flaws to drive billions of calls to American phones.

Explanation:

5 0

2 years ago

The number of protons determines what __________ a particular atom belongs to.

MatroZZZ [7]

<span>The number of protons determines what __________ a particular atom belongs to.

Answer = The number of protons </span><span>determines what element a particular atom belongs to.

So the correct and best answer choice is C. element.

Hope this helps.</span>

4 0

4 years ago