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
Nutka1998 [239]
3 years ago
10

A ball is dropped from a window and takes two seconds to reach the ground .it starts from rest and reaches a final speed of 20m/

a .what is the balls acceleration?
Physics
1 answer:
Akimi4 [234]3 years ago
3 0
The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .

If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .

(Gravity on Earth is only 9.8 m/s^2.)
You might be interested in
A 3250 N car is pushed a distance of 35 m the power was 11375 J, how long did it take?
irakobra [83]

Answer:

10.8s

Explanation:

Given parameters:

Force on the car  = 3250N

Distance  = 35m

Power  = 11375W

Unknown:

Time taken = ?

Solution:

To solve this problem;

 Power is the rate at which work is done

         Power = \frac{work done }{time}  

  Work done  = force x distance  = 3250 x 35  = 123200J

Now;

          11375  = \frac{123200}{t}  

           11375t  = 123200  

                   t  = 10.8s

5 0
3 years ago
A mass-spring system has k = 56.8 N/m and m = 0.46 kg.
andriy [413]

Answer:

A. \omega=11.1121\ rad.s^{-1}

B. f=1.7685\ Hz

C. T=0.5654\ s

Explanation:

Given:

  • spring constant, k=56.8\ N.m^{-1}
  • mass attached, m=0.46\ kg

A)

for a spring-mass system the frequency is given as:

\omega=\sqrt{\frac{k}{m} }

\omega=\sqrt{\frac{56.8}{0.46}}

\omega=11.1121\ rad.s^{-1}

B)

frequency is given as:

f=\frac{\omega}{2\pi}

f=\frac{11.1121}{2\pi}

f=1.7685\ Hz

C)

Time period of a simple harmonic motion is given as:

T=\frac{1}{f}

T=0.5654\ s

7 0
3 years ago
What is the pressure at a depth of 15 cm brine of density 1.2/cm³? ​
Anna [14]

P = density × gravity acceleration × height

P = 1200 × 9.81 × 15/100

P = 1765.8

6 0
3 years ago
Read 2 more answers
A soap box derby car at the top of a ramp has more _________ energy and at the finish line at the bottom of the ramp it has more
astra-53 [7]
Kinetic, potential because, at the top of the ramp it’s going faster. Potential at the bottom of the ramp is potential because, it’s not doing any motion.
5 0
3 years ago
In a game of pool, the cue ball moves at a speed of 2 m/s toward the eight ball. When the cue ball hits the eight ball, the cue
agasfer [191]

Answer:

a)  p₀ = 1.2 kg m / s,  b) p_f = 1.2 kg m / s,  c)   θ = 12.36, d)  v_{2f} = 1.278 m/s

Explanation:

a system formed by the two balls, which are isolated and the forces during the collision are internal, therefore the moment is conserved

a) the initial impulse is

        p₀ = m v₁₀ + 0

        p₀ = 0.6 2

        p₀ = 1.2 kg m / s

b) as the system is isolated, the moment is conserved so

       p_f = 1.2 kg m / s

we define a reference system where the x-axis coincides with the initial movement of the cue ball

we write the final moment for each axis

X axis

        p₀ₓ = 1.2 kg m / s

        p_{fx} = m v1f cos 20 + m v2f cos θ

        p₀ = p_f

       1.2 = 0.6 (-0.8) cos 20+ 0.6 v_{2f} cos θ

        1.2482 = v_{2f} cos θ

Y axis  

       p_{oy} = 0

       p_{fy} = m v_{1f} sin 20 + m v_{2f} cos θ

       0 = 0.6 (-0.8) sin 20 + 0.6 v_{2f} sin θ

       0.2736 = v_{2f} sin θ

we write our system of equations

        0.2736 = v_{2f} sin θ

        1.2482 = v_{2f} cos θ

divide to solve

        0.219 = tan θ

         θ = tan⁻¹ 0.21919

         θ = 12.36

let's look for speed

           0.2736 = v_{2f} sin θ

            v_{2f} = 0.2736 / sin 12.36

           v_{2f} = 1.278 m / s

7 0
2 years ago
Other questions:
  • An auto, starting from rest, undergoes constant acceleration and covers a distance of 1200 meters. The final speed of the auto i
    15·1 answer
  • 1. Your new designer chair has an S-shaped tubular metal frame that behaves just like a spring. When your friend, who weighs 600
    14·1 answer
  • Which is most buoyant in water? F) wood H) lead weight G) penny J) sugar
    15·2 answers
  • Which one of the following statements does not accurately describe the diatonic scale as it corresponds to the setup on a piano
    14·2 answers
  • The unit of potential is the?
    14·1 answer
  • A box of mass 3 kg is lifted 1.5 m onto a shelf. Calculate the change in its gravitational potential energy. The gravitational f
    10·2 answers
  • The net external force on the propeller of a 0.75 kg model airplane is 17N forward. What is the
    11·1 answer
  • A man lifts a 200 pound barbell over his head using 890 Newtons of force. It traveled a distance of 2.4 meters. Calculate the wo
    5·1 answer
  • In a single movable pulley, a load of 500 N is lifted by applying 300 N effort. Calculate MA, VR and efficiency.​
    9·1 answer
  • The cylinder valve is open and the gas is collected and atmospheric pressure
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!