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
katen-ka-za [31]
2 years ago
9

A rock is tossed straight up from ground level with a speed of 22 m/s. When it returns, it falls into a hole 9.0 m deep. a. What

is the rock’s velocity as it hits the bottom of the hole? b. How long is the rock in the air, from the instant it is released until it hits the bottom of the hole?
Physics
1 answer:
Vera_Pavlovna [14]2 years ago
5 0

Answer:

(a) v_{f}=26.08m/s

(b) t=4.906seconds

Explanation:

We will take ground level as origin and upward is positive direction

the givens are

y_{i}=0\\y_{f}=-9.0m\\ v_{i}=22m/s

Part (a)

To find the final velocity we use the kinematic equation

So

(v_{f})^{2} =(v_{i})^{2} +2a(y_{f}-y_{i})\\(v_{f})^{2}=(22m/s)^{2}+2(-9.8m/s^{2} ) (-10-0)\\v_{f}=\sqrt{(22m/s)^{2}+2(-9.8m/s^{2} ) (-10-0)} \\v_{f}=26.08m/s

Part (b)

To find time of rock trip until it touches the ground we will use simple kinematic equation or simple motion equation

v_{f}=v_{i}+at\\t=\frac{v_{f}-v_{i}}{a}\\ t=\frac{(-26.08m/s)-(22m/s)}{-9.8m/s^{2} }\\t=4.906seconds

Notice that we substituted vf with negative sign because its direction is downwards

You might be interested in
You drive 6.00 km at 50.0 km/h and then another 6.00kmat 900 km/h Your average speed over
Cerrena [4.2K]

Explanation:

average speed = total distance travelled / total time travelled

time to travel the first 6km: 6 / 50 = 3/25 (h)

time to travel the next 6km: 6 / 90 = 1/15 (h)

[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]

The total time: 3/25 + 1/15 = 14/75 (h)

Average speed over the 12 km drive will be:

\frac{12}{ \frac{14}{75} }  =  \frac{450}{7}  = 64.3 \: km{h}^{ - 1}

8 0
2 years ago
What would be the daughter product of the beta decay of lead-212 and what would be the daughter product of the alpha decay of po
kati45 [8]

Answer:

lead with Z = 82 is transformed into Bismuth with Z = 73

The Po with Z = 84 becomes Pb with Z = 82

Explanation:

Beta decay occurs when a neutron emits an electron and an anti neutrino from the atomic nucleus, therefore the atomic number of the material increases by one unit.

           Pb + e + ν → Bi

lead with Z = 82 is transformed into Bismuth with Z = 73

In alpha decay, a helium nucleus is emitted from the nucleus of the atom, therefore the atomic number decreases by two units.

         Po +α → Pb

The Po with Z = 84 becomes Pb with Z = 82

4 0
2 years ago
When was the most gravitational potential energy stored between the model and Earth? Assume that the model's mass did not change
Lyrx [107]

Answer:

As the ball falls from C to E, potential energy is converted to kinetic energy. The velocity of the ball increases as it falls, which means that the ball attains its greatest velocity, and thus its greatest kinetic energy

Explanation:

8 0
2 years ago
A ball is dropped off the balcony of a hotel room and it takes 2.8s to fall to the ground . how high above the ground is the bal
RideAnS [48]

The height of the ball above the ground is 38.45 m

First we will calculate the velocity of the ball when it touch the ground by using first equation of motion

v=u+gt

v=0+9.81×2.8

v=27.468 m/s

now the height of the ground can be calculated by the formula

v=√2gh

27.468=√2×9.81×h

h=38.45 m

5 0
2 years ago
Are colavent bonds more likely to be found in compounds contaning both materals and nonmetals or compounds contaning only nonmet
atroni [7]

Answer:

bonds between 2 alike atoms or most non-metals get a covalent bond when reacting to the ... It tells what kinds of atomas are in a compound and how many.

Hope this helped

-Gavin

7 0
2 years ago
Read 2 more answers
Other questions:
  • What is one example of the use of an infrared sensor? A. detecting the presence of humans trapped under collapsed buildings. B.
    8·2 answers
  • Electrons are accelerated through a voltage difference of 230 kV inside a high voltage accelerator tube. What is the final kinet
    9·1 answer
  • Why is gasoline so flammable
    8·2 answers
  • Providing that it does not collide with another object, what is the most likely reason that an object moving through space would
    15·1 answer
  • A ball drops some distance and gains 30 J of kinetic energy. How much gravitational potential energy did the ball start with? Do
    12·1 answer
  • A 70.0-kilogram man is walking at a speed if 2.0 m/s. What is the kinetic energy?
    6·1 answer
  • A planet has a circular orbit around a star. It is a distance of 53,000,000 km from the centre of the star.
    14·1 answer
  • HELPPP BESTIESSS An astronomer is studying two stars that have about the same size and brightness. From the Earth, one of the st
    8·2 answers
  • Vhich type of reaction is modeled by this chemical equation?<br> PLi + CaCl2 - 2LICI + Ca
    13·1 answer
  • The angle of incidence for a ray of light passing through the centre of curvature of a concave mirror is.
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!