All categories

3 years ago

How much kinetic energy does a person of mass 50kg running at 3m/s have? Provide

Physics

1 answer:

ddd [48]3 years ago

4 0

Answer:

0.225 KJ kinetic energy is used for a person of mass 50 Kg running at speed of 3 m/s.

Explanation:

Given:

mass = 50 kg

velocity = v = 3 m/s

To Find :

Kinetic energy = ?

Solution:

Kinetic energy of an object is the energy that it possesses due to its motion.

The formula for kinetic energy is given as

$\textrm{kinetic energy} = \frac{1}{2}\times mass\times velocity^{2}\\= \frac{1}{2}\times m\times v^{2}\\= \frac{1}{2}\times 50\times 3^{2}\\= 25\times 9\\= 225\ Joules.$

But we required kinetic energy in KiloJoules i.e KJ

1 K = 1000 = $10^{3}$

$\textrm{kinetic energy} = 225\ J\\= 0.225\times 1000\\= 0.225 \times 10^{3}\\= 0.225\ KJ$

You might be interested in

The acceleration of a bus is given by ax (t) = at, where a = 1.2 m/s3.If the bus's velocity at time t = 1.0s is 5.0 m/s, what is

goldenfox [79]

We are given the acceleration of the bus as a function of time:

a(t) = 1.2t

Let the velocity also be a function of time v(t).

Since a(t) is the change of v(t) over time, we can use the fundamental theorem of calculus to determine the velocity at t = 2s, or v(2), given that:

a(t) = 1.2t

v(1) = 5

v(2) - v(1) = $\int\limits^2_1{a(t)}\,dt$

v(2) - 5 = $\int\limits^2_1{1.2t}\,dt$

v(2) - 5 = 0.6t² evaluated between t = 1 and t = 2

v(2) - 5 = 0.6(4) - 0.6(1)

v(2) = 1.8 + 5

v(2) = 6.8m/s

3 0

3 years ago

I need to know how long the friend will drive before he meets me and how many miles I will have traveled by the time I meet him,

IceJOKER [234]

Let you be at point A while your friend be at point B,
while you are still having lunch,
you friend travels= 27/60*75miles/h=33.75miles
Remaining Distance= 135miles-33.75miles=101.25miles
Take note here is the tricky part, for the remaining distance both you and your friend are driving towards each other,
So first,
Total speed =Adding both ur friend and ur speed= 60+75=135miles/h
Time taken to meet= 101.25miles/135miles/h=0.75h
Total hours ur friend drives= 0.75h+27/60h=1.2h
total distance ur friend drove= 1.2h * 75miles/h= 90km
for the part how far u travelled,
simply take 135miles -90miles=45miles

4 0

3 years ago

How do the properties of waves correspond with observations of waves?

Sveta_85 [38]

Answer:

no sabo por q no mi entender

7 0

3 years ago

How is it possible for one electrically neutral atom to exert an electrostatic force on other electrically neutral atom?

Free_Kalibri [48]

Answer:

Explained

Explanation:

Although Atom are electrically neutral. But atom atom is combination of nucleus and electrons. The nucleus of the atom is composed neutron and positively charged protons. On the outside of nucleus at some distance are the electrons which are negatively charged. So, there is difference in position of the two differently charge species. So, this way a electrically neutral atom can exert a electrostatic force on other electrically neutral atom

8 0

4 years ago

A cart, which has a mass of m - 2.50 kg, is sitting at the top of an inclined plane which is 3.30 meters long and which meets th

SashulF [63]

Answer:

Part(i) the time taken for this cart to reach the bottom of the inclined plane is 1.457 s

Part(ii) the velocity of the cart when it reaches the bottom of the inclined plane is 4.531 m/s

Part(iii) the kinetic energy of the cart when it reaches the bottom of the inclined plane is 25.663 J

Explanation:

Given;

mass of the cart = 2.5 kg

angle of inclination, β = 18.5⁰

length of inclined plane = 3.3m

Part(i) the time taken for this cart to reach the bottom of the inclined plane

s = ut + ¹/₂×at²

initial vertical velocity, u = 0

s = 3.3 m

s = ¹/₂×at²

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

acceleration, of the cart, a = gsinβ

a = 9.8sin(18.5) = 3.11 m/s²

$t = \sqrt{\frac{2X3.3}{3.11 }}= 1.457 s$

Part(ii) the velocity of the cart when it reaches the bottom of the inclined plane

V = a×t

V = 3.11 × 1.457 = 4.531 m/s

Part(iii) the kinetic energy of the cart when it reaches the bottom of the inclined plane

KE = ¹/₂MV²

= ¹/₂ × 2.5× (4.531)²

= 25.663 J

6 0

4 years ago