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
tresset_1 [31]
1 year ago
13

A 55 kg track and field athlete has an average power output of 5.4 kW during the 200 meter dash. How quickly did she finish the

race?
Group of answer choices

a. 20 s

b. 22 s

c. 23 s

d. 18 s
Physics
1 answer:
olga_2 [115]1 year ago
5 0

The time taken for the athlete to finish the race is 20 s (Option A)

<h3>What is power? </h3>

Power is simply defined as the rate at which work is done. It can be expressed mathematically as

Power (P) = work (W) / time (t)

But

Work = weight × distance

Therefore,

Power = (weight × distance ) / time

<h3>How to determine the time </h3>
  • Mass (m) = 55 Kg
  • Acceleration due to gravity (g) = 9.8 m/s²
  • Weight = mg = 55 × 9.8 = 539 N
  • Power (P) = 5.4 KW = 5.4 × 1000 = 5400 W
  • Distance (d) = 200 m
  • Time (t) =?

Power = (weight × distance ) / time

5400 = (539 × 200) / t

5400 = 107800 / t

Cross multiply

5400 × t = 107800

Divide both side by 5400

t = 107800 / 5400

t = 20 s

Learn more about power:

brainly.com/question/5684937

#SPJ1

You might be interested in
Can I get the answer
ANEK [815]
Hey there
how are u..................................................
4 0
3 years ago
A car is moving at 19 m/s along a curve on a horizontal plane with radius of curvature 49m.
JulsSmile [24]

Answer:

\mu =0.75

Explanation:

<u>Frictional Force </u>

When the car is moving along the curve, it receives a force that tries to take it from the road. It's called centripetal force and the formula to compute it is:

F_c=m.a_c

The centripetal acceleration a_c is computed as

\displaystyle a_c=\frac{v^2}{r}

Where v is the tangent speed of the car and r is the radius of curvature. Replacing the formula into the first one

F_c=m.\frac{v^2}{r}

For the car to keep on the track, the friction must have the exact same value of the centripetal force and balance the forces. The friction force is computed as

F_r=\mu N

The normal force N is equal to the weight of the car, thus

F_r=\mu .m.g

Equating both forces

\displaystyle \mu .m.g=m.\frac{v^2}{r}

Simplifying

\displaystyle \mu =\frac{v^2}{rg}

Substituting the values

\displaystyle \mu =\frac{19^2}{(49)(9.8)}

\boxed{\mu =0.75}

7 0
3 years ago
This is a change in an object's position. <br> Net Force<br> Gravitational Pull<br> Motion<br> Force
alexira [117]

Answer:

Motion

Explanation:

because when something moves its call motion

3 0
3 years ago
Compare the benefits of wildfires to grasslands, northern forests, and deciduous forests.
Dimas [21]
Wildfires benefit grasslands, northern forests, and deciduous forests. Grasslands are benefited by improved soil quality and control of tree cover. Invertebrate species diversity is maintained through wildfire as well. Northern forests, like grasslands, experience increased production and nutritional quality of food as a result of wildfires. Deciduous forests experience an increase in the nutritional quality of food as well, but the effects are more temporary. The amount of shrubs in deciduous forests is reduced as a result of wildfires, allowing more herbaceous plants such as mosses and lichens to grow.
6 0
3 years ago
Read 2 more answers
A sports car and a minivan run out of gas and are pushed to the side of the road. Which is easier to push, and why?
Olin [163]

Answer: d

Explanation:

4 0
3 years ago
Read 2 more answers
Other questions:
  • The time needed for a wave to make one complete cycle is its
    10·1 answer
  • The illustration represents one form of _________________, the process that enables all stars, including our sun, to continuousl
    12·2 answers
  • An engineer in a locomotive sees a car stuck on the track at a railroad crossing in front of the train. When the engineer first
    9·1 answer
  • How is energy conserved in a process of a heart beat
    10·1 answer
  • A watermelon cannon fires a watermelon vertically up into the air at a velocity of +9.5m/s, starting from an initial position of
    11·1 answer
  • The closest approach distance between Mars and Earth is about 56 million km. Assume you can travel in a spaceship at 58,000 km/h
    8·1 answer
  • The net external force on the propeller of a 0.75 kg model airplane is 17N forward. What is the
    11·1 answer
  • 10 points
    10·1 answer
  • Which nucleus completes the following equation?
    7·1 answer
  • One one-thousandth is expressed by which prefix?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!