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
Dima020 [189]
3 years ago
8

A small dog is trained to jump straight up a distance of 1.2 m. How much kinetic energy does the 7.2-kg dog need to jump this hi

gh? (The acceleration due to gravity is 9.8 m/s2.) Show your work for credit.
Physics
1 answer:
LUCKY_DIMON [66]3 years ago
8 0
Answer:84.672 joules.

Explanation:

1) Data:

m = 7.2 kg
h = 1.2 m
g = 9.8 m / s²

2) Physical principle

Using the law of mechanical energy conservation principle, you have that the kinetic energy of the dog, when it jumps, must be equal to the final gravitational potential energy.

3) Calculations:

The gravitational potential energy, PE, is equal to m × g × h

So, PE = m × g × h = 7.2 kg × 9.8 m/s² × 1.2 m = 84.672 joules.

And that is the kinetic energy that the dog needs.
You might be interested in
An engine that has an efficiency of 25% takes in 200 [J] of heat during each cycle. Calculate the amount of work this engine per
BartSMP [9]

Answer:

W=50J

Explanation:

The work done W and the energy taken Q_{in} by a heat engine are related to the efficiency \eta by the expression

\eta=\frac{W}{Q_{in}}

The efficiency is \eta=25%, the numerical form of this percentage is 0.25 and the energy taken is Q_{in}=200J. Replacing in the formula:

0.25=\frac{W}{200}\\W=200*0.25\\W=50J

5 0
3 years ago
A pelican flying along a horizontal path drops a fish from a height of 4.7 m. The fish travels 9.3 m horizontally before it hits
slavikrds [6]

Answer:

(A) 9.5 m/s

(B) 5.225 m

Explanation:

vertical height (h) = 4.7 m

horizontal distance (d) = 9.3 m

acceleration due to gravity (g) = 9.8 m/s^{2}

initial speed of the fish (u) = 0 m/s

(A) what is the pelicans initial speed ?

  • lets first calculate the time it took the fish to fall

s = ut + (\frac{1}{2}) at^{2}

since u = 0

s =  (\frac{1}{2}) at^{2}

t = \sqrt{\frac{2s}{a} }

where a = acceleration due to gravity and s = vertical height

t = \sqrt{\frac{2 x 4.7 }{9.8} } = 0.98 s

  • pelicans initial speed = speed of the fish

speed of the fish = distance / time = 9.3 / 0.98 = 9.5 m/s

initial speed of the pelican = 9.5 m/s

(B) If the pelican was traveling at the same speed but was only 1.5 m above the water, how far would the fish travel horizontally before hitting the water below?

vertical height = 1.5 m

pelican's speed = 9.5 m/s

  • lets also calculate the time it will take the fish to fall

s = ut + (\frac{1}{2}) at^{2}

since u = 0

s =  (\frac{1}{2}) at^{2}

t = \sqrt{\frac{2s}{a} }

where a = acceleration due to gravity and s = vertical height

t = \sqrt{\frac{2 x 1.5 }{9.8} } = 0.55 s

 

distance traveled by the fish = speed x time = 9.5 x 0.55 = 5.225 m

8 0
3 years ago
How do you think the amount of a material affects its tendency to sink or float?
Viktor [21]

Answer:

Things float when they are positively buoyant, or less dense than the fluid in which they are sitting. This does not mean that an object has to be lighter than the fluid, as in the case of a boat; objects just need to have a greater ratio of empty space to mass than the fluid.

Explanation:

pls mark as brainliest

6 0
3 years ago
Explain Newton's third law in your own words.
Kazeer [188]
Newton's third law states "for every action, there is an equal and opposite reaction."

What this is pretty much saying is that for every action, there is a consequence. One force connects and triggers another.
5 0
3 years ago
Read 2 more answers
If the average time it takes for the cart from point 1 to point 2 is 0.2 s, calculate the angle θ from the horizontal of the tra
inn [45]

Answer:

hehe

Explanation:

I dont know because I am a noob ant study

5 0
2 years ago
Other questions:
  • a cart is loaded with a brick and pulled up at a constant speed along an inclined plane to the height of a seattop. if the mass
    9·2 answers
  • Why is it that parents establish a positive relationship and positive communication with babies and young children
    13·1 answer
  • What is the formula for calculating the net force of an object
    10·1 answer
  • At the surface of Jupiter's moon Io, the acceleration due to gravity is 1.81 m/s2m/s2 . A watermelon has a weight of 56.0 NN at
    9·2 answers
  • What is the wavelength of a wave whose velocity is 8 m/s and frequency is 2 waves/second?
    7·1 answer
  • A cube of wood 15.0 cm on each side is tied to the bottom of a tank filled with water to a depth of 50 cm. The tension in the st
    14·1 answer
  • Your friend says their laptop speakers
    10·1 answer
  • Find the ratio of the Coulomb electric force Fe to the gravitational force Fo between two
    10·1 answer
  • Khi phân cực thuận Diode có dòng điện chạy theo chiều
    7·1 answer
  • CCL4 is Non polar and NH3 is Polar? Why?​
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!