A 75kg man climbs the stairs to the fifth floor of a building. A total hieght of 16m. His potential energy has increased by

A 500 W immersion heater is placed in a pot containing 1.00 L of water at 20oC. (a) How long will the water take to rise to the

tatiyna

Answer:

96 s.

Explanation:

(a)

From the question,

Q = cm(t₂-t₁)................... Equation 1

Where Q = heat required to boil the water, c = specific heat capacity of the water, m = mass of the water, t₂ = final temperature of water, t₁ = initial temperature of water

Note: The boiling point of water = 100 °C

Given: c = 4200 J/kg.°C, t₂ = 100 °C, t₁ = 20 °C

mass of water = density×volume

m = D×v, Where D = 1000 kg/m³, v = 1.00 L = 0.001 m³

Hence, m = 1000×0.001 = 1 kg.

Substitute into equation 1

Q = 4200×1(100-20)

Q = 4200×8

Q = 33600 J.

But,

P = Q/t................... Equation 2

make t the subject of the equation

t = Q/P................. Equation 3

Where P = power, t = time

From the question,

70 % of the available energy is absorbed by water.

P = 0.7×500 = 350 W.

Substitute into equation 2

t = 33600/350

t = 96 s.

6 0

3 years ago

Which is true about using energy? There is an unlimited amount of energy in the universe. When energy is used, it disappears for

frutty [35]

Answer:

3. When energy is used, it can transform to new types but can never disappear.

Explanation: it can transform into heat, light, ect and will never disapear unlessed turned of.

7 0

3 years ago

Under what circumstances can energy level transitions occur?

Yuliya22 [10]

Answer:

Energy transition therefore occurs due to the amount of kinetic energy gained by the electrons. The electrons with higher kinetic energy are excited to the higher level (excited state) compare to the electron with low kinetic energy (this energy are energy in the ground state)

Explanation:

Energy level transition occur when light rays strikes a metal surface to emit electron from the surface, a term known as photoelectric effect. This amount of electron emitted from the surface depends on the speed of light ray striking the metal surface.

Energy transition therefore occurs due to the amount of kinetic energy gained by the electrons. The electrons with higher kinetic energy are excited to the higher level (excited state) compare to the electron with low kinetic energy (this energy are energy in the ground state)

8 0

3 years ago

An automobile to be transported by ship is raised 8.2m above the dock. If it's GPE is 63,405 J what is the car's mass?

Pepsi [2]

Answer:

m = 788.2[kg]

Explanation:

The potential energy of a body is defined as the product of mass by gravitational acceleration by height. And it can be calculated by means of the following equation.

$E_{pot}=m*g*h$

where:

Epot = potential energy = 63405 [J]

m = mass [kg]

g = gravity acceleration = 9.81[m/s²]

h = elevation = 8.2[m]

Now replacing:

$63405=m*9.81*8.2\\m=788.2[kg]$

5 0

3 years ago

Which mystery primate is a biped? list the characteristics you choose to justify your answer

Vadim26 [7]

Primate B mystery primate is a biped.

The characteristics are:

The vast majority of primates live in trees (Notable exceptions are humans and gorillas).
The majority of primates have upright upper bodies and occasionally walk on two feet (Humans are erect and always exhibit bipedalism).
All primates have smaller noses and matching olfactory brain regions (except Lemurs).
Compared to other mammals, primates have enormous brains for their size. Stereoscopic vision, hand-eye coordination, and manual dexterity are all governed by the brain's enlarged regions.
Considering the size of the animal, long gestations
Primate sociality is rather high in general.
The majority of primates are nocturnal.
The highly enjoyable action of grooming is shared by all highly evolved primates, including humans.

<h3>Primate </h3>

Lemurs, lorises, tarsiers, monkeys, apes, and humans are all included in the biological order called primates. Class Mammalian of the phylum Vertebrate includes creatures with qualities that have evolved recently in the taxonomic classification of the animal kingdom. 19 subtaxa known as orders have been added to the Mammalia classification. Primates are one of such groups, which contains eutherian animals like monkeys and apes. As a result, during a period of 30 million years, new world and old world monkeys underwent different adaptive radiations and were reproductively isolated. The Oligocene epoch saw the evolution of prosimians. About 30 million years ago, all currently extant primates underwent evolution.

Which mystery primate is a biped? list the characteristics you choose to justify your answer

Learn more about primate here:

brainly.com/question/16671781

#SPJ4

6 0

2 years ago