1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Ghella [55]
3 years ago
13

Two friends, Al and Jo, have a combined mass of 195 kg. At the ice skating rink, they stand close together on skates, at rest an

d facing each other. Using their arms, they push on each other for 1 second and move off in opposite directions. Al moves off with a speed of 10.2 m/sec in one direction and Jo moves off with a speed of 11.4 m/sec in the other. You can assume friction is negligible. Find Al's mass
Physics
1 answer:
ddd [48]3 years ago
5 0

Answer:

Al's mass is 102.92  kg  

Explanation:

As there are no external forces in the horizontal direction, the horizontal net force must be zero:

F_{net} = 0

As the force is the derivative in time of the momentum, this means that the horizontal momentum is constant:

F_{net} = \frac{dp_{horizontal}}{dt} = 0

p_{horizontal_i }= p_{horizontal_f}

where the suffix i and f means initial and final respectively.

The initial momentum will be:

p_{horizontal_}i = m_{Al} \ v_{Al_i} + m_{Jo} \ v_{Jo_i}

But, as they are at rest, initially

p_{horizontal_i} = m_{Al} * 0 + m_{Jo} * 0

p_{horizontal_i} = 0

So, this means:

p_{horizontal_f} = m_{Al} \ v_{Al_f} + m_{Jo} \ v_{Jo_f} = 0

We know that the have an combined mass of 195 kg:

m_{total} = m_{Al} + m_{Jo} = 195 \ kg.

so:

m_{Jo} = 195 \ kg - m_{Al}.

m_{Al} \ v_{Al_f} + (195 \ kg - m_{Al}) \ v_{Jo_f} = 0

m_{Al} \  v_{Al_f} - m_{Al} \  v_{Jo_f}= - 195 \ kg \  v_{Jo_f}

m_{Al} \ (v_{Al_f} - v_{Jo_f})= - 195 \ kg \ v_{Jo_f}

m_{Al} = \frac{ - 195 \ kg \ v_{Jo_f} } {  v_{Al_f} - v_{Jo_f} }

m_{Al} = \frac{195 \ kg  \ v_{Jo_f} } {    v_{Jo_f} - v_{Al_f} }

Now, we can use the values:

v_{Al_f}= 10.2 \frac{m}{s}

v_{Jo_f}= - 11.4 \frac{m}{s}

where the minus sign appears as they are moving at opposite directions

m_{Al} = \frac{195 \ kg  ( - 11.4 \frac{m}{s} ) } {   (- 11.4 \frac{m}{s}) - 10.2 \frac{m}{s} }

m_{Al} = 102.92 \ kg

and this is the Al's mass.

You might be interested in
Identifying the factors contributing to and acting as determinant factors of health disparities during the program theory and de
Sav [38]

Answer:

a) True

Explanation:

A program-specific message provided to an individual or group with the intention of raising awareness of a health condition, motivating behavior change, removing perceived barriers to participating in a health habit, or something else relating to the program's aims and objectives. The most effective intervention messages are usually theory-based and culturally adapted.

5 0
2 years ago
Two loudspeakers emit sound waves along the x-axis. A listener in front of both speakers hears a maximum sound intensity when sp
yKpoI14uk [10]

Answer

given,

difference between the two consecutive maximum

λ = 0.870 - 0.540

λ = 0.33 m

speed of sound = 340 m/s

b) frequency of the sound

v = f x λ

340 = f x 0.33

f =\dfrac{340}{0.33}

    f = 1030.3 Hz

a) phase difference

  the expression of phase difference is given by

   \phi = \dfrac{2\pi}{\lambda}\ \delta

   \delta = \Delta x - \lambda

   \delta = 0.540 - 0.33

   \delta = 0.21\ m

now,

   \phi = \dfrac{2\pi}{\lambda}\ \times 0.21

   \phi = \dfrac{2\pi}{0.33}\ \times 0.21

   \phi = 3.99 rad

8 0
3 years ago
You exert 20 newtons of force on the hammer to remove the nail. The hammer exerts 90
andrezito [222]

Answer:

20 n

Explanation:

7 0
2 years ago
A train moves uniform velocity of 36km/h for 15 sec.find distance
vesna_86 [32]

Answer:

S = V × t

Explanation:

first convert 36km/h to m/s

36km/h=36*5/18=180/18=10m/s

d =s*t

=10*10=100m

5 0
2 years ago
The instrument which is commonly used to measure the intensity of radioactivity is called a
tatyana61 [14]
The instrument is a Geiger counter and is used to measure radioactive level around people's bodies.
4 0
3 years ago
Read 2 more answers
Other questions:
  • carlis lives 100 m away from his friend home what is his average speed if he reaches his friends home in 50s
    10·1 answer
  • the force of attraction between two masses is 3.60 Newtons if one of the masses is tripled and the distance between the masses i
    8·1 answer
  • What is a change that will not affect the pressure in a container
    6·2 answers
  • In most cases, a multicellular organism is not an exact copy of its parents because it
    10·2 answers
  • I NEED A QUESTION ON THE CONSERVATION OF MECHANICAL ENERGY AND THE ANSWER PLEASE
    5·1 answer
  • Calculate (A⃗ ×B⃗ )⋅C⃗ for the three vectors A⃗ with magnitude A = 4.86 and angle θA = 23.5 ∘ measured in the sense from the +x
    13·1 answer
  • Can you pls give a question about science. like why does the sky blue? PLS HELPPP ASAP ​
    11·1 answer
  • A baby leaves a bowl of food on the floor and crawls westwards to fetch a toy placed 5 m away.At the same time a dog walks eastw
    13·1 answer
  • What is general relativity​
    6·1 answer
  • 3. Two fans blow at 5 ms^-1 in a easterly direction and 8ms^-1 in a Northerly
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!