• The net force acting on an object equals the applied force plus the force of friction.

In the Daytona 500 auto race, a Ford Thunderbird and a Mercedes Benz are moving side by side down a straightaway at 78.5 m/s. Th

Andrews [41]

Answer:

FT is 1020.6 meters (1640.6 meters - 620 meters) far from MB

Explanation:

First you have to consider that the Ford Thunderbird (FT) follows a rectilinear motion with varying acceleration, while Mercedez Benz (MB) has a constant velocity (no acceleration). So if you finde the time spent by FT in each section, and the distance, then you will find the distance for MB.

1) Vf² = Vi² + 2ad, where Vf: final velocity, Vi: ionitial velocity, a: acceleration and d: distance.

For the first portion (0 m/s)² = (78.5 m/s)² + 2a(250 m) ⇒

-(78.5 m/s)² / 2(250m) = a ⇒ a = -12.3 m/s².

Now, you can find the corresponding time for this section with the following formule: Vf = Vi + at ⇒ 0 m/s = 78.5 m/s + (-12.3 m/s²) t

⇒ t= (-78.5 m/s)/ (-12.3 m/s²) ⇒ t= 6.4 seconds.

2) Then FT spent 5 seconds in the pit.

3) The the FT accelerates until reach 78.5 m/s again in a distance of 370 m.

Vf² = Vi² + 2ad ⇒ (78.5 m/s)² = (0 m/s)² + 2a(370 m)

⇒ (78.5 m/s)²/ 2(370 m) = a ⇒ a = 8.3 m/s²

Then, Vf = Vi + at ⇒ 78.5 m/s = 0 m/2 + (8.3 m/s²) t

⇒ (78.5 m/s)/(8.3 m/s²) = t ⇒ t = 9.5 seconds.

4) Summarizing, the FT moves 620 meters (250 + 370 mts) in 20.9 seconds ( 6.4 s + 5 s + 9.5 s).

5) During this time, MB moves

Velocity = distance/ time ⇒ Velocity x time = Distance

⇒ Distance = (78.5 m/s) x (20.9 seconds) ⇒ Distance = 1640.6 meters

6) Finally, the FT is 1020.6 meters (1640.6 meters - 620 meters) far from MB

3 0

3 years ago

Find the net work done by friction on the body of a snake slithering in a complete circle of radius. The coefficient of friction

Tamiku [17]

Answer:

C. 0 J

Explanation:

When an object moves in a circle, friction provides the centripetal force. Hence, it is acting towards the centre of the circle. The displacement of the object is tangential to the circle at the point of interest. Hence, the angle between the frictional force and the displacement is 90°.

Work done is given by

W = Fd cos θ

where F is the force, d is the displacement and θ is the angle between them.

W = Fd cos 90° = 0 J

Hence, the work done by friction is 0 J.

7 0

3 years ago

Please help on this one!!

inysia [295]

The energy transformations that occur as you coast down long hill on a bicycle, including the brakes to make the bike stop at the bottom, is that at the top of the hill you have high GPE AND LOW KE, on your way down you have HIGH KE AND LOW GPE, and at the bottom you have thermal energy due to the stop of the brakes.

the law of conversation of energy and describe the energy transformations that occur as you coast down a long hill on a bicycle and then apply the brakes to make the bike stop at the bottom.

3 0

3 years ago

A 49 N coconut is in a 15 m tree. What is te potential energy of the coconut?

eduard

Answer:

735 J

Explanation:

From the question given above, the following data were obtained:

Weight (W) = 49 N

Height (h) = 15 m

Potential energy =?

Potential energy is simply defined as the product of weight of the object and height to which the object is raised. Mathematically, it is expressed as:

Potential energy = weight × height

With the above formula, we can obtain the potential energy of the coconut as follow:

Weight (W) = 49 N

Height (h) = 15 m

Potential energy =?

Potential energy = weight × height

Potential energy = 49 × 15

Potential energy = 735 J

Thus, the potential energy of the coconut is 735 J

4 0

3 years ago

4. How do ordinary objects behave in microgravity?

Nikolay [14]

Answer:

Bubbles paused

Explanation:

the air bubble doesn't rise because it is no lighter than the water around it—there's no buoyancy. The droplet doesn't fall from the leaf because there's no force to pull it off. It's stuck there by molecular adhesion.

for instance, onto the International Space Station, gravity becomes negligible, and the laws of physics act differently than here on Earth

On Earth, the buoyancy of the air bubbles causes them to rise to the top together, creating a segregation between air and water. However, in microgravity, nothing forces the air bubbles to interact and thus rise together, Green said.

8 0

3 years ago