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
nadezda [96]
3 years ago
7

PLEASE HELP An object is thrown upward with an initial velocity of 32.1 m/s. What is its velocity in 4.0 s? (use g = 9.81 m/s2).

Please include step by step process. -7.14 11.2 7.14 -4.6
Physics
1 answer:
grigory [225]3 years ago
6 0

Answer:

-7.14

Explanation:

According to equation of motion

v = u + at

where

v is the final velocity at any time t

u is the initial velocity

a is the acceleration

and t is the time

___________________________________________

Given

An object is thrown upward it means

its initial velocity is in upward direction

but acceleration due to gravity is in downward direction which will cause to decrease the velocity of object.

Intial velocity u = 31.1 m/s

final velocity v at 4 second we have to find.

t = 4 second

a = g = 9.81 m/s2 (it is acting in opposite direction of motion hence its sign will be negative ).

Thus

a = -  9.81 m/s2

using the above values in v = u + at

v = 32.1 - 9.81*4

v = 32.1 - 39.24

v = -7.14

Thus, correct option is -7.14.

You might be interested in
A gazelle leaps from a cliff 2.5 m high with a speed of 5.6m/s.
trapecia [35]

Initial speed of Gazelle is along x direction and its value will be

v_x = 5.6 m/s

also its initial height is given as

y = 2.5 m

Part a)

now from kinematics along Y direction

\Delta y = v_y t + \frac{1}{2} at^2

as we know that

\Delta y = 0

v_y = 0

a = 9.8 m/s^2

2.5 = 0 + \frac{1}{2} (9.8) t^2

t = 0.714 s

Part b)

distance moved horizontally

\Delta x = v_x t

as we know that

v_x = 5.6 m/s

now we will have

v_x = 5.6 (0.714) = 4m

so it will lend at distance of 4 m.

Part c)

final velocity in vertical direction

v_{fy} = v_y + at

v_{fy} = 0 + (9.8)(0.714) = 7 m/s

v_x = 5.6 m/s

so net speed will be

v^2 = v_x^2 + v_y^2

v^2 = 7^2 + 5.6^2

v = 8.96 m/s

7 0
4 years ago
Help please ! USA test prep
Illusion [34]
C) 2 ohms I think don't fully trust my answer I suck at math but I think it's c
3 0
3 years ago
If your parasympathetic nervous system was activated what might you be doing?
Bezzdna [24]
A. Relaxing under a tree.

The parasympathetic nervous system is known as the “rest and digest” system. Activities that require as little movement as possible help the heart rate to slow down. The other activities would be associated with the Sympathetic nervous system which is known as the “fight or flight,” or when your heart rate is up and running.
8 0
3 years ago
As the boat in which he is riding approaches a dock at 3.0 m/s, Jasper stands up in the boat and jumps toward the dock. Jasper a
Annette [7]
Im pretty sure it’s a because it makes more sense you know?.
5 0
3 years ago
ASAP I will give 34 points please give a good answer
liraira [26]
Well, what's a well? Basically, to obtain water found in an aquifer, a well is a hole drilled into the earth. To pull water from the soil, a pipe and a pump are used and a screen filters out un Wells are drilled into the rock as deep as 1,000 feet to enter the water. ... Through a well pump, water flows through this casing. Above level, the well structure is closed off. From a pipe connected between the casing and a pressure tank (generally located in the basement of your house), the water then reaches your home.
6 0
3 years ago
Read 2 more answers
Other questions:
  • What is the science of how geothermal energy is collected?
    8·1 answer
  • Heating causes an object to dxpena
    8·1 answer
  • Mars rotates on its axis once every 1.02 days (almost the same as Earth does). (a) Find the distance from Mars at which a satell
    6·1 answer
  • If the speed of the dart is v0 just before it strikes the apple, how high does the apple move upward because of its collision wi
    5·1 answer
  • if a body moves with 20 km per hour in first 1 hour 30 km per hour in second one hour 40 kilometre per hour in third one hour wh
    12·1 answer
  • What do you do abt onion eyes (MY EYES ARE BURNING BADDD)
    6·1 answer
  • How will the element Ca + O bond ?
    11·2 answers
  • The number of waves that pass a given point in a second is___.
    5·1 answer
  • "two pieces of iron attract eachother. how can you tell whether they are both magnets?"
    9·1 answer
  • Is snowflakes forming in a cloud a chemical or physical change
    15·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!