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3 years ago

A race car circles 10 times around a circular 8.0-km track in 20 min.

2 answers:

6 0

Find the average speed and the average velocity.

Average speed = distance / time

distance = 10 x 8000 m = 80,000 m
time = 20 min * 60 s/min = 1200 s

Average speed = 80,000 m / 1200 s = 66.67 m/s

Average velocity = displacement / time

Given that the race car made complete circles the final poin is the same initial point, then its displacement is zero and the average velocity is zero too.

fredd [130]3 years ago

5 0

Assuming that you're asking for the average speed,

Average speed = distance / time

since he circle 8 km track 10 times, the distance is 80,000 m and the time is 20 min or 1200 seconds
Average speed = 80,000 / 1200 = 66.67 m/s

Hope this helps

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two charges experience exert a force of 1n on each other when they are 1m apart. what force will these charges experience if the

Kisachek [45]

The force experienced by the charges when they are placed 2 m apart will be 0.25 N.

The force between two charges is given by Coulomb’s Law.

According to this law, the force between two charges varies inversely as the square of the distance between the charges and is directly proportional to the product of the magnitude of the two charges.

The above statement is represented by the following equation,

F= K Q1 x Q2/r^2

Here, F = Force between the two charges

K = Constant

Q1 and Q2 = Magnitude of the two charges

r = Separation between the two charges

According to this equation, the force is inversely proportional to the square of the distance between two charges.

Initially, when the two charges are 1 m apart, the force is 1 N.

When the distance between the two charges is doubled,

then according to Coulomb’s Law, the force should decrease by 4 times.

Hence, if the charges are placed 2 meters apart, the force becomes 1/4= 0.25 N.

To know more about "Coulomb's Law", refer to the following link:

brainly.com/question/9261306?referrer=searchResults

#SPJ4

8 0

1 year ago

A dumbbell-shaped object is composed by two equal masses, m, connected by a rod of negligible mass and length r. If I_1 is the m

Paraphin [41]

Answer:

I2>I1

Explanation:

This problem can be solved by using the parallel axis theorem. If the axis of rotation of a rigid body (with moment of inertia I1 at its center of mass) is changed, then, the new moment of inertia is gven by:

$I_2=I_{1}+Md^2$

where M is the mass of the object and d is the distance of the new axis to the axis of the center of mass.

It is clear that I2 is greater than I1 by the contribution of the term Md^2.

I2>I1

hope this helps!!

8 0

3 years ago

6. A lumberjack is standing on a log floating on a lake. She starts from rest, then runs along the log to the end, when she jump

scoray [572]

Answer:

a) -3.267 m/s

b) 2.227 m/s

Explanation:

As per the conservation of momentum

m1v1 + m2v2=0

m1= mass of log

m2 = mass of lumber jack

v1 = velocity of log

v2 = velocity of lumber jack

a) Velocity of first log

$-\frac{70*7}{150} = -3.267$ m/s

b) m1v1 + m2v2 = m3v3

Velocity of log

= $\frac{70*7}{150+70} \\2.227$

4 0

3 years ago

An 82.0 kg spacewalking astronaut pushes off a 655 kg satellite, exerting a 95.0 N force for the 0.530 s it takes him to straigh

Tcecarenko [31]

Answer:

41.41 m

Explanation:

When force F is applied on an object of mass m for time t and velocity v₁ is created

F X t = mv₁

F = 95 N , t = .53 s, m = 655 kg

95 x .53 = 655 x v₁

v₁ = .0768 m/s

Applying conservation of momentum on man and satellite

m₁ v₁ = m₂v₂

655 x .0768 = 82 xv₂

v₂ = .6134 m/s

their relative velocity

= .6134 + .0768

= .6902 ( they are in opposite direction )

After 60 second distance between them

= 60 x .6902 m

= 41.41 m

6 0

3 years ago

A string of length 100 cm is held fixed at both ends and vibrates in a standing wave pattern. The wavelengths of the constituent

azamat

The wavelengths of the constituent travelling waves CANNOT be 400 cm.

The given parameters:

<em>Length of the string, L = 100 cm</em>

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The wavelengths of the constituent travelling waves is calculated as follows;

$L = \frac{n \lambda}{2} \\\\n\lambda = 2L\\\\\lambda = \frac{2L}{n}$

for first mode: n = 1

$\lambda = \frac{2\times 100 \ cm}{1} \\\\\lambda = 200 \ cm$

for second mode: n = 2

$\lambda = \frac{2L}{2} = L = 100 \ cm$

For the third mode: n = 3

$\lambda = \frac{2L}{3} \\\\\lambda = \frac{2 \times 100}{3} = 67 \ cm$

For fourth mode: n = 4

$\lambda = \frac{2L}{4} \\\\\lambda = \frac{2 \times 100}{4} = 50 \ cm$

Thus, we can conclude that, the wavelengths of the constituent travelling waves CANNOT be 400 cm.

The complete question is below:

A string of length 100 cm is held fixed at both ends and vibrates in a standing wave pattern. The wavelengths of the constituent travelling waves CANNOT be:

A. 400 cm

B. 200 cm

C. 100 cm

D. 67 cm

E. 50 cm

Learn more about wavelengths of travelling waves here: brainly.com/question/19249186

5 0

3 years ago