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3 years ago

10

The cunninghams are moving across the country. Mr.cunningham leaves 2.5 hours before mrs.cunningham. If he averages 40 mph and s

he averages 65 mph,how long will it take Mrs.cunningham to overtake mr.cunningham?

1 answer:

Eva8 [605]3 years ago

5 0

When she starts out, he is (40x2.5)= 100 miles ahead of her.

She gains (65-40)= 25 miles on him every hour.

It takes her (100/25)= 4 hours to catch up to him.

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What would happen if both the radius and mass of a planet were cut in half

Shtirlitz [24]

Explanation:

According to formula

g = GM/R^2

when mass is halved the value of g becomes half but when radius is halved the value of g increases 4 times.

As a result of both value of g becomes twice.

5 0

3 years ago

At an amusement park there is a ride in which cylindrically shaped chambers spin around a central axis. People sit in seats faci

Klio2033 [76]

Answer:

The radius of a chamber is 2.36 meters.

Explanation:

Given that,

The outer wall moves at a speed of 2.72 m/s.

Mass of the person, m = 75.1 kg

The person feels a force of 235 N force pressing against his back. The force acting on the person is centripetal force. It is given by the below formula :

$F=\dfrac{mv^2}{r}$

r is the radius of a chamber

$r=\dfrac{mv^2}{F}$

$r=\dfrac{75.1\times (2.72)^2}{235}$

r = 2.36 meters

So, the radius of a chamber is 2.36 meters. Hence, this is the required solution.

7 0

3 years ago

A metal can containing condensed mushroom soup has mass 215 g, height 10.8 cm, and diameter 6.38 cm. It is placed at rest on its

s344n2d4d5 [400]

Answer:

Part a)

Moment of inertia of the cylinder is given as

$I = 1.21 \times 10^{-4} kg m^2$

Part B)

Height of the cylinder is of no use here to calculate the inertia

Part C)

Since we don't know about the viscosity data of the soup inside the cylinder so we can't say directly about the moment of inertia of the cylinder as $I = 1/2 mR^2$

Explanation:

As we know that the inclined plane is of length L = 3 m

and its inclination is given as 25 degree

so we know that acceleration of center of mass of the cylinder is constant so we will have

$v_f^2 = v_i^2 + 2 a L$

so we have

$v_f^2 = 0 + 2a(3)$

now we know that

$v_{avg} = \frac{L}{t} = \frac{v_f + v_i}{2}$

$\frac{3}{1.50} = \frac{v_f + 0}{2}$

$v_f = 4 m/s$

Now we have know that final speed of the cylinder due to pure rolling is given as

$v_f = \sqrt{\frac{2gH}{1 + \frac{I}{mR^2}}}$

$4 = \sqrt{\frac{2(9.81)(3 sin25)}{1 + \frac{I}{0.215(0.0319)^2}}}$

$I = 1.21 \times 10^[-4} kg m^2$

Part B)

Height of the cylinder is of no use here to calculate the inertia

Part C)

Since we don't know about the viscosity data of the soup inside the cylinder so we can't say directly about the moment of inertia of the cylinder as $I = 1/2 mR^2$

8 0

3 years ago

In a wire with a 1.05 mm2 cross-sectional area, 7.93×1020 electrons flow past any point during 3.97 s. What is the current ????

34kurt

Answer:

The current in the wire is 31.96 A.

Explanation:

The current in the wire can be calculated as follows:

$I = \frac{q}{t}$

<u>Where</u>:

q: is the electric charge transferred through the surface

t: is the time

The charge, q, is:

$q = n*e$

<u>Where</u>:

n: is the number of electrons = 7.93x10²⁰

e: is the electron's charge = 1.6x10⁻¹⁹ C

$q = n*e = 7.93 \cdot 10^{20}*1.6 \cdot 10^{-19} C = 126.88 C$

Hence, the current in the wire is:

$I = \frac{126.88 C}{3.97 s} = 31.96 A$

Therefore, the current in the wire is 31.96 A.

I hope it helps you!

3 0

3 years ago

An 8.7 g bullet is accelerated in a rifle barrel 105 cm long to a speed of 465 m/s. Use the work-energy theorem to find the aver

Viktor [21]

Answer:896 N

Explanation:

Given

mass of bullet $m=8.7 gm$

Length of barrel $d=105 cm=1.05 m$

final velocity $v=465 m/s$

initial velocity $u=0 m/s$

Work done by all the forces is equal to change in kinetic Energy

$F\cdot d=\frac{1}{2}\times mv^2-0$

$F_{avg}\times 1.05=\frac{1}{2}\times 8.7\times 10^{-3}\times 465^2$

$F_{avg}=\frac{0.5\times 8.7\times 10^{-3}\times 465^2}{1.05}$

$F_{avg}=895.789 Na\pprox 896 N$

6 0

3 years ago