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
erastovalidia [21]
3 years ago
14

A 60 kilogram student jumps down from a laboratory counter. At the instant he lands on the floor hus speed is 3 meters per secon

d. If the student stops in .2 second what is thw average force of floor on the student
Physics
1 answer:
erastovalidia [21]3 years ago
5 0

As per Newton's law rate of change in momentum is net force

so we can write it as

F = \frac{dP}{dt}

F = \frac{m(v_f - v_i)}{\Delta t}

now we know that

m = 60 kg

v_f = 3 m/s

v_i = 0

\Delta t= 0.2 s

from above equation

F = \frac{60(3 - 0)}{0.2} = 900 N

so he will experience 900 N force in above case

You might be interested in
9. Magnesium 9 (Mg), Calcium (Ca) and Barium (Ba) are all in the same group on the periodic
stiks02 [169]

Answer:

C. They all react with substances in similar ways

Explanation:

First of all, let's define a few quantities:

- Atomic number: it is the number of protons in the nucleus of an atom. For neutral atoms, the atomic number is also equal to the number of electrons in the atom (since neutral atoms have same number of protons and electrons)

- Valence electrons: these are the electrons in the most external shell of the atom. When the outermost shell is full, the element does not react, since it does not easily gain/give away electrons. When the outermost shell is not full, the atom tends to gain or give away electrons in order to complete this shell, so the atom is more reactive.

Now we can analyze the different statements:

A. They all have the same atomic number  --> false: magnesium has atomic number 12, calcium has atomic number 20, barium has atomic number 56

B. They all have the same number of electrons  --> false: since the atomic number of the 3 elements is different, they have different number of electrons

C. They all react with substances in similar ways  --> true: these 3 elements are all in the same group of the periodic table, this means they have the same number of valence electrons, so they all react in the same way

D. They were all discovered by Dmitri Mendeleev --> false: these elements were already known before Mendeleev, he just re-arranged them into the periodic table

3 0
4 years ago
Lasers can be constructed that produce an extremely high intensity electromagnetic wave for a brief time—called pulsed lasers. T
MAVERICK [17]

Explanation:

It is given that,

Maximum electric field, E=10^{11}\ V/m

Time taken, t=1\ ns=10^{-9}\ s

(a) Maximum magnetic field, B=\dfrac{E}{c}

B=\dfrac{10^{11}\ V/m}{3\times 10^8\ m/s}

B = 333.33 T

(b) Intensity of beam, I=\dfrac{E^2}{2\mu_o c}

I=\dfrac{(10^{11})^2}{2\times 4\pi \times 10^{-7}\times 3\times 10^8}

I=1.32\times 10^{19}\ W/m^2

(c) Energy delivered by the pulse, E=I\times A\times t

E=1.32\times 10^{19}\times 10^{-6}\times 10^{-9}

E = 13200 J

Hence, this is the required solution.

8 0
3 years ago
If you wished to warm 100 kg of water by 15 degrees celsius for your bath, how much heat would be required? (give your answer in
Anit [1.1K]
For the answer to the question above, 
<span>Q = amount of heat (kJ) </span>
<span>cp = specific heat capacity (kJ/kg.K) = 4.187 kJ/kgK </span>
<span>m = mass (kg) </span>
<span>dT = temperature difference between hot and cold side (K). Note: dt in °C = dt in Kelvin </span>

<span>Q = 100kg * (4.187 kJ/kgK) * 15 K </span>
<span>Q = 6,280.5 KJ = 6,280,500 J = 1,501,075.5 cal</span>
6 0
3 years ago
What is an example of a non contact force
olchik [2.2K]

Answer: Gravitational force

Explanation:

A non contact force can be described as a force applied to an object by another body that is not in direct contact with it.

For example, an object thrown upwards will return back due to the force of gravity acting on it. So, it means Gravitational force is acting on the body without necessarily being in contact with that body.

8 0
4 years ago
Which does a reference point provide? Select two options. a position from which to measure future distance a set of standard uni
In-s [12.5K]

Answer:

hope this helps you :)

Explanation:

An object is in motion if its position changes relative to another object. To decide if you are moving, you can use your chair as a reference point. A reference point is a place or object used for comparison to determine if something is in motion.

4 0
4 years ago
Other questions:
  • Instructions: Select the correct answer.Why does air at 75% relative humidity and 30eC make your skin feel stickier than air at
    10·1 answer
  • When traveling from air to a solid, what would you expect a sound wave to do?
    11·2 answers
  • NEED AN ANSWER ASAP!
    12·1 answer
  • In a chemical reaction, the total mass of the reactants is 10.0 grams. The total mass of the products must be:
    5·1 answer
  • A string of length L is under tension, and the speed of a wave in the string is v. What will be the speed of a wave in the strin
    5·1 answer
  • 6. What power is used by a machine to perform 800 J of work in 25 s?​
    8·1 answer
  • Ions form bonds by __________ electrons.
    12·2 answers
  • Lab Report
    12·1 answer
  • A proton is observed to have an instantaneous acceleration 11*10^11. what is the magnitude of e of the electric field at the pro
    14·1 answer
  • In recent years, astronomers have found planets orbiting nearby stars that are quite different from planets in our solar system.
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!