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3 years ago

An 850.0 kg car wants to accelerate from rest to a speed of 18.0 m/s.

Physics

1 answer:

strojnjashka [21]3 years ago

8 0

Answer:

$1.07*10^5 Joules$

Explanation:

From Kinetic energy K.E = m* $v^2$ /2

Where mass of the car, m = 850 kg

velocity of the car, v = 18 m/s

Hence K.E = $850*18^2/2 = 1.07*10^5 Joules$

Also, we can evaluate the given time

time = K.E / Power

= $1.07*10^5 / (50*746)$

= 2.87 secs

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Free runners jump long distances and land on the ground or a wall. How do they apply Newton’s second law to lessen the force of

Veseljchak [2.6K]

As we know that as per Newton's II law we have

$F = \frac{dP}{dt}$

here we will have

$dP$ = change in momentum

$dt$ = time interval in which momentum is changed

now in order to have least injury during jumping we need to have least force on the jumper

so in order to have least force we can say that the momentum must have to change in maximum time so that amount of force must be least

So we need to increase the time in which momentum of the system is changed

5 0

3 years ago

a truck was traveling at 16.6 miles per second and accelerates at a rate of 2.0 meters per second squared how much time is requi

Ivan

A truck was traveling at 16.6 miles per second and accelerates at a rate of 2.0 meters per second squared then time is required for the truck to reach a speed of 25 miles per second is 6759 s.

Explanation:

Velocity is defined as the rate of change in displacement while acceleration is defined as the rate of change of velocity. Acceleration may be positive or negative. Acceleration is positive when the velocity of the object is increases and it is negative when velocity of the object is decreases. Negative acceleration is also called deceleration.

Mathematically

a = $\frac{(v_{f} - v_{i})}{t}$

Where a is the acceleration of the object, $v_{f}$ is the final velocity of the object and $v_{i}$ is the initial velocity of the object. t is equal to time taken.

Given data:

$v_{f}$ = 25 miles/s

$v_{i}$ = 16.6 miles/s

a = 2.0 m/s²

t = ?

As velocities and acceleration given in different units, So we need to convert to obtain same units. Here we convert unit of acceleration from m/s² to miles/s².

1 m/s² = 0.000621371192 miles/s²

2 m/s² = 0.00124274238 miles/s²

So,

a = 0.00124274238 miles/s²

Apply formula

a = $\frac{v_{f} - v_{i}}{t}$

t = $\frac{(v_{f} - v_{i})}{a}$

t = $\frac{(25 - 16.6)}{0.00124274238}$

t = 6759 s

Learn more about velocity and acceleration from

brainly.com/question/1192983

#learnwithBrainly

3 0

3 years ago

Which of the following are true (choose all that apply)? Sound can travel through a vacuum. -Sound can travel through water. Lig

Lunna [17]

Answer:

option (A) - false

option (B) - true

option (C) - true

option (D) - true

option (E) - true

option (F) - true

Explanation:

The sound waves are mechanical waves that means they need a medium to travel.

The light waves are non mechanical waves it means they do not need a medium to travel.

Sound cannot travel trough vacuum.

Sound can travel through air and water.

Light can travel trough vacuum and in air and in water.

7 0

3 years ago

A circular loop of wire with radius 2.00 cm and resistance 0.600 Ω is in a region of a spatially uniform magnetic field B⃗ that

Anika [276]

Answer:

Incomplete questions

Let assume we are asked to find

Calculate the induced emf in the coil at any time, let say t=2

And induced current

Explanation:

Flux is given as

Φ=NAB

Where

N is number of turn, N=1

A=area=πr²

Since r=2cm=0.02

A=π(0.02)²=0.001257m²

B=magnetic field

B(t)=Bo•e−t/τ,

Where Bo=3T

τ=0.5s

B(t)=3e(−t/0.5)

B(t)=3exp(-2t)

Therefore

Φ=NAB

Φ=0.001257×3•exp(-2t)

Φ=0.00377exp(-2t)

Now,

Induce emf is given as

E= - dΦ/dt

E= - 0.00377×-2 exp(-2t)

E=0.00754exp(-2t)

At t=2

E=0.00754exp(-4)

E=0.000138V

E=0.138mV

b. Induce current

From ohms laws

V=iR

Given that R=0.6Ω

i=V/R

i=0.000138/0.6

i=0.00023A

i=0.23mA

5 0

3 years ago

A spherical balloon is made from a material whose mass is 3.30 kg. The thickness of the material is negligible compared to the 1

stellarik [79]

Answer:

563712.04903 Pa

Explanation:

m = Mass of material = 3.3 kg

r = Radius of sphere = 1.25 m

v = Volume of balloon = $\frac{4}{3}\pi r^3$

M = Molar mass of helium = $4.0026\times 10^{-3}\ kg/mol$

$\rho$ = Density of surrounding air = $1.19\ kg/m^3$

R = Gas constant = 8.314 J/mol K

T = Temperature = 345 K

Weight of balloon + Weight of helium = Weight of air displaced

$mg+m_{He}g=\rho vg\\\Rightarrow m_{He}=\rho vg-m\\\Rightarrow m_{He}=1.19\times \frac{4}{3}\pi 1.25^3-3.3\\\Rightarrow m_{He}=6.4356\ kg$

Mass of helium is 6.4356 kg

Moles of helium

$n=\frac{m}{M}\\\Rightarrow n=\frac{6.4356}{4.0026\times 10^{-3}}\\\Rightarrow n=1607.85489$

Ideal gas law

$P=\frac{nRT}{v}\\\Rightarrow P=\frac{1607.85489\times 8.314\times 345}{\frac{4}{3}\pi 1.25^3}\\\Rightarrow P=563712.04903\ Pa$

The absolute pressure of the Helium gas is 563712.04903 Pa

3 0

3 years ago