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
9966 [12]
3 years ago
15

A ball is dropped from rest at height of 20m. If it loses 25% of its kinetic energy when it strikes the ground. What is the heig

ht to which it bounces?
Physics
1 answer:
victus00 [196]3 years ago
6 0

Answer:

15 meters

Explanation:

The inicial energy of the ball is just potencial energy, and its value is:

E = m * g * h = m * g * 20,

where m is the ball mass, and g is the value of gravity.

In the moment that the ball strickes the ground, all potencial energy transformed into kinetic energy, and 25% of this energy is lost, so the total energy at this moment will be:

E' = 0.75 * E = 0.75 * m * g * 20 = 15*m*g

This kinetic energy will make the ball goes up again, and at the maximum height, all kinetic energy is transformed back into potencial energy.

So, as the mass and the gravity are constants, we can calculate the height the ball will reach:

E' = m*g*h = 15*m*g -> h = 15 meters

You might be interested in
Lucia raced her car on a raceway
denpristay [2]

Answer:

Good question to ask in physics, sir maam

8 0
2 years ago
Read 2 more answers
On a frictionless horizontal air table, puck A (with mass 0.254 kg ) is moving toward puck B (with mass 0.367 kg ), which is ini
irinina [24]

Answer:

v_a=0.8176 m/s

\Delta K=0.07969 J - 0.0849 J = -0.00521 J

Explanation:

According to the law of conservation of linear momentum, the total momentum of both pucks won't be changed regardless of their interaction if no external forces are acting on the system.

Being m_a and m_b the masses of pucks a and b respectively, the initial momentum of the system is

M_1=m_av_a+m_bv_b

Since b is initially at rest

M_1=m_av_a

After the collision and being v'_a and v'_b the respective velocities, the total momentum is

M_2=m_av'_a+m_bv'_b

Both momentums are equal, thus

m_av_a=m_av'_a+m_bv'_b

Solving for v_a

v_a=\frac{m_av'_a+m_bv'_b}{m_a}

v_a=\frac{0.254Kg\times (-0.123 m/s)+0.367Kg (0.651m/s)}{0.254Kg}

v_a=0.8176 m/s

The initial kinetic energy can be found as (provided puck b is at rest)

K_1=\frac{1}{2}m_av_a^2

K_1=\frac{1}{2}(0.254Kg) (0.8176m/s)^2=0.0849 J

The final kinetic energy is

K_2=\frac{1}{2}m_av_a'^2+\frac{1}{2}m_bv_b'^2

K_2=\frac{1}{2}0.254Kg (-0.123m/s)^2+\frac{1}{2}0.367Kg (0.651m/s)^2=0.07969 J

The change of kinetic energy is

\Delta K=0.07969 J - 0.0849 J = -0.00521 J

3 0
3 years ago
A concave mirror has a focal length of 13.5 cm. This mirror forms an image located 37.5 cm in front of the mirror. Find the magn
77julia77 [94]

Explanation:

It is given that,

Focal length of the concave mirror, f = -13.5 cm

Image distance, v = -37.5 cm (in front of mirror)

Let u is the object distance. It can be calculated using the mirror's formula as :

\dfrac{1}{v}+\dfrac{1}{u}=\dfrac{1}{f}

\dfrac{1}{u}=\dfrac{1}{f}-\dfrac{1}{v}

\dfrac{1}{u}=\dfrac{1}{(-13.5)}-\dfrac{1}{(-37.5)}

u = -21.09 cm

The magnification of the mirror is given by :

m=\dfrac{-v}{u}

m=\dfrac{-(-37.5)}{(-21.09)}

m = -1.77

So, the magnification produced by the mirror is (-1.77). Hence, this is the required solution.

7 0
3 years ago
Sarah walks WEST a distance of 5 meters then turns NORTH and walks 8
Leokris [45]

Answer:

she is 3 meters in north

Explanation:

3 0
2 years ago
How to answer this question?
laila [671]

Answer:

measure the vector diagram first

5 0
2 years ago
Other questions:
  • An object is dropped from a platform 100 feet high. Ignoring wind resistance, what will its speed be when it reaches the ground?
    10·1 answer
  • How are chargeable cells different from ordinary dry cells​
    13·1 answer
  • The difference in energy () between vibrational energy levels is determined by the nature of the bond. If a photon of light poss
    15·1 answer
  • What is the wave speed if a wave has a frequency of 12 hz and a wavelength of 3.0 m?
    13·1 answer
  • Why we cannt cook food on high attitude (like mountain where exist low temperatures )? ​
    9·1 answer
  • Give some example acostic using "ELEMENTS"
    9·1 answer
  • How did the transcontinental railroad impact travel?
    11·1 answer
  • La resultante de dos fuerzas perpendiculares aplicadas a un mismo cuerpo es 11.18 N y el módulo de una de ellas es de 10 N. ¿Cuá
    7·1 answer
  • El profesor pide a juan que le indique tres magnitudes de su libro de texto y el le contesta; su peso, tamaño y el diseño de la
    13·1 answer
  • Which statement best defines an electric field?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!