Which of the following statements is true?

Exercice 1

Mariana [72]

Answer:

Injections of aqueous solution of fruct

levulose of formula C, H, O,,

For

prevent dehydration such solutions are obtained

dissolving a mass m = 25g of fructose for a volume of 50

final solution.

1.1 Calculate the molecular molar mass of fructose

1.2 Determine the amount of corresponding fructose material

1.3 Calculate the molar concentration of these fructose solutions

1.4

6 0

3 years ago

Elena (60.0 kg) and Madison (65.0 kg) are ice-skating at the Rockefeller ice rink in New Yok city. Their friend Tanner sees Elen

Bas_tet [7]

1. +72.0 kg m/s

The momentum of an object is given by:

p = mv

where

m is the mass of the object

v is its velocity

Taking "to the right" as positive direction, for Elena we have

m = 60.0 kg is the mass

v = +1.20 m/s is the velocity

So, Elena's momentum is

$p_e=(60.0 kg)(+1.20 m/s)=+72.0 kg m/s$

2. -162.5 kg m/s

Here Madison is moving in the opposite direction of Elena (to the left), so her velocity is

v = -2.50 m/s

while her mass is

m = 65.0 kg

Therefore, her momentum is

$p_m= (65.0 kg)(-2.50 m/s)=-162.5 kg m/s$

3. -90.5 kg m/s

The total momentum of Elena and Madison is equal to the algebraic sum of their momenta; taking into account the correct signs, we have:

$p=p_e + p_m = +72.0 kg m/s - 162.5 kg m/s =-90.5 kg m/s$

4. 0.72 m/s to the left

We can find the final speed of Elena and Madison by using the law of conservation of momentum. In fact, the final momentum must be equal to the initial momentum (before the collision).

The initial momentum is the one calculated at the previous step:

$p_i = -90.5 kg m/s$

while the final momentum (after the collision) is given by

$p_f = (m_e + m_m) v$

where

$m_e$ is Elena's mass

$m_m$ is Madison's mass

v is their final velocity

According to the law of conservation of momentum,

$p_i = p_f\\p_i = (m_e + m_m) v$

So we can find v:

$v=\frac{p_i}{m_e + m_m}=\frac{-90.5 kg m/s}{60.0 kg+65.0 kg}=-0.72 m/s$

and the direction is to the left, since the sign is negative.

8 0

3 years ago

A cruise ship travels across a river at 25 meters per minute. If the river is 6200 meters wide, how long

EleoNora [17]

Answer:

248 minutes

Explanation:

6200/25=248

This means there is 248 25s in 6200

which means it will take 248 minutes to travel through the river

Also here's a neat trick:

The units for speed is meters/minute

The units for distance is meters

Dividing distance by speed will cancel out the meters and leave only the speed.

3 0

3 years ago

The mass of a proton is approximately equal to

Dahasolnce [82]

Answer:

$1.6726\cdot 10^{-27} kg$

Explanation:

The three main particles that make an atom are:

- Proton: its mass is $1.6726\cdot 10^{-27} kg$ , it carries an electric charge of +e ( $e=1.6\cdot 10^{-19}C$ ), and it is located in the nucles of the atom

- Neutron: its mass is $1.6749 \cdot 10^{-27}kg$ , it carries no electric charge, and it is also located in the nucleus of the atom

- Electron: its mass is $9.1094 \cdot 10^{-31}kg$ , it carries an electric charge of -e ( $e=1.6\cdot 10^{-19}C$ ), and it is located outside the nucleus