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
kirill [66]
3 years ago
5

A ball is thrown down vertically with an initial speed of 20 m/s from a height of 60 m. Find (a) its speed just before it strike

s the ground and (b) how long it takes for the ball to reach the ground. Repeat (a) and (b) for the ball thrown directly up from the same height and with the same initial speed.
Physics
1 answer:
vivado [14]3 years ago
3 0

Answer:

Explanation:

Ball is thrown downward:

initial velocity, u = - 20 m/s (downward)

height, h = - 60 m

Acceleration due to gravity, g = - 9.8 m/s^2 (downward)

(a) Let the speed of the ball as it hits the ground is v.

Use third equation of motion

v^{2}=u^{2}+2as

v^{2}=(-20)^{2}+2\times 9.8 \times 60

v = 39.69 m/s

(b) Let t be the time taken

Use First equation of motion

v = u + a t

- 39.69 = - 20 - 9.8 t

t = 2 second

Now the ball is thrown upwards:

initial velocity, u = 20 m/s (upward)

height, h = - 60 m

Acceleration due to gravity, g = - 9.8 m/s^2 (downward)

(c) Let the speed of the ball as it hits the ground is v.

Use third equation of motion

v^{2}=u^{2}+2as

v^{2}=(-20)^{2}+2\times 9.8 \times 60

v = 39.69 m/s

(d) Let t be the time taken

Use First equation of motion

v = u + a t

- 39.69 = + 20 - 9.8 t

t = 6.09 second

You might be interested in
While an emf source supplies energy to a circuit, that energy is dissipated when the current passes through resistance. In deali
fredd [130]

The question is incomplete, the options are;

RI^2

I^2/R

R/I^2

R/V^2

RV^2

V^2/R

VI

VIR

Select all that apply

Answer:

P=RI^2

P=V^2/R

P=VI

Explanation:

Power is the rate at which energy is changing in a circuit. It is shown by the formulas outlined above from the group of answer choices. Since the current (I), voltage (V), and resistance (R) were mentioned in the question, any of three three formulas could be used to obtain the power drawn by the conductor.

7 0
3 years ago
HELP!!!!! Please hurry up
Degger [83]

it's def. TRUE. i got the same question and i got it right

6 0
3 years ago
Read 2 more answers
The partial negative charge in a molecule of water occurs because
just olya [345]

the electrons shared between the oxygen and hydrogen atoms spend more time around the oxygen atom nucleus than around the hydrogen atom nucleus

4 0
3 years ago
The _______ is a factor that's affected by changes in the independent variable. A. dependent variable B. hypothesis C. experimen
Irina18 [472]
A. dependent variable

As the the independent variable (i.e. number of cats being sold) increases, the dependent variable (i.e. money made) will also increase. You can have 1,000,000 cats for sale and make no money, but you cannot make money without having sold some cats first.
Hope my weird example helped!
7 0
3 years ago
Read 2 more answers
Which of the following are NOT examples of digital information storage?
VikaD [51]
Vinyl records because it’s not a secure information storage
3 0
3 years ago
Read 2 more answers
Other questions:
  • An isotope of the element fluorine has 9 protons and 10 neutrons. What is the name of this isotope? fluorine-
    11·2 answers
  • a metal sphere with a mass of 90 kg rolls along at 16m/s and strikes a stationary sphere having a mass of 140kg. the first spher
    14·1 answer
  • How does the mass of an object affect the outcome when an unbalanced force acts on it?
    11·1 answer
  • Volcanic eruptions are natural phenomena in the . They sometimes erupt, spilling out lava and dust. The lava solidifies, forming
    7·1 answer
  • During the process of _____, two rails or sides break apart and attract new nucleotide bases to form a new and complete strand.
    11·1 answer
  • What is the importance of law of conservation of mass
    12·1 answer
  • How many significant figures does 1700000000 have ?
    12·2 answers
  • Which of the following technologies would produce the least energy in light
    9·1 answer
  • What is the relation between liquid pressure and density of liquid<br><br><br>plzz fast ​
    8·2 answers
  • Developing a Claim
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!