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2 years ago

Please help need to know ASAP.

2 answers:

8 0

Answer: because she is pedalling at her maximum speed produced by the maximum force applied. At constant speed, acceleration is equal to zero.

Explanation:

Pedalling of bicycle involves application of force. The force applied produces circular motion to the tires which eventually transform into linear speed.

V = wr

Where V = linear speed

W = angular speed

r = radius.

Change in speed V will lead to acceleration or deceleration depending on increase or decrease in speed.

If she stops accelerating, then, she must have applied force that makes her pedalling at maximum speed. She is also maintaining this uniform (constant ) speed. After reaching her maximum speed.

At constant speed, acceleration = 0

Base on this explanation, even though she is still pedalling as fast as she can, which at constant speed, she will stop accelerating and her speed reaches a maximum value because she is pedalling at her applied maximum force.

emmainna [20.7K]2 years ago

3 0

Answer:

Resistive forces get bigger as the speed increases and eventually they reach the point where the pedalling forces become balanced and therefore there is no further acceleration.

Explanation:

Hope this helps:))

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A car is traveling to the right with a speed of 29m/s when the rider slams on the accelerator to pass another car. The car pas

adoni [48]

Answer:

Acceleration of the car is $1.43\ m/s^2$ .

Explanation:

It is given that,

Initial speed of the car, u = 29 m/s

Finally it reaches a speed of, v = 34 m/s

Distance, d = 110 m

We need to find the acceleration of the car as it speed up. It can be calculated using third law of motion as :

$v^2-u^2=2ad$

$a=\dfrac{v^2-u^2}{2d}$

$a=\dfrac{(34)^2-(29)^2}{2\times 110}$

$a=1.43\ m/s^2$

So, the acceleration of the car as it speeds up is $1.43\ m/s^2$ . Hence, this is the required solution.

6 0

3 years ago

When three people with a total mass of 2.00 x 102 kg step into their 1.200 x 103 kg car, the car’s

Aleksandr-060686 [28]

Answer:

$k = 457333.3 N/m$

$x_a =0.09\ m$

Explanation:

From the question we are told that

The total mass of three people is $M = 2.00*10^{2} \ kg$

The mass of the car is $m_c = 1.200 *10^{3} \ kg$

The compression of the car spring is $x = 3 \ cm = 0.03 \ m$

Generally the spring constant is mathematically represented as

$k = \frac{F}{x}$

Here F is the force exerted by the mass of three people and that of the car , this is mathematically represented as

=> $F = (M +m_c) *g$

=> $F = ([2.0*10^{2} ]+[ 1.200*10^{3}]) * 9.8$

=> $F = 13720 \ N$

$k = \frac{13720}{0.03}$

=> $k = 457333.3 N/m$

Generally if the mass which the car is loaded with is $m = 3.00*10^{2} \ kg$

Then the force experienced by the spring is

=> $F_a = (m +m_c) *g$

=> $F_a = (3.00*10^{3} + 1.200 *10^{3}) * 9.8$

=> $F_a = 41160 \ N$

Generally from the above formula the compression is

$x_a = \frac{F_a}{k}$

=> $x_a = \frac{41160}{457333.3}$

=> $x_a =0.09\ m$

3 0

3 years ago

A disk ring of inner radius a and outer radius b lying on the y − z plane has a uniform surface electric charge density +σ(>

solmaris [256]

Answer:

a) V = k 2π σ (√(b² + x²) - √ (a² + x²)) ,

b) E = - k 2π σ x (1 /√(b² + x²) - 1 /√(a² + x²))

Explanation:

a) The expression for the electric potential is

V = k ∫ dq / r

For this case, consider the disk formed by a series of concentric rings of radius r and width dr, the distance of each ring to point P

R = √(x² + r²)

The charge on a ring is

σ = dq / dA

The area of a ring is

A = π r

dA = 2π r dr

So the charge is

dq = σ 2π r dr

We substitute

V = k σ 2pi ∫ r dr / √(r² + x²)

We integrate

V = k 2π σ √(r² + x²)

We evaluate from the lower limit r = a to the upper limit r = b

V = k 2π σ (√(b² + x²) - √ (a² + x²))

b) the electric field and the potential are related

E = - dV / dx

E = - k 2π σ (1/2 2x /√(b² + x²) - ½ 2x /√(a² + x²))

E = - k 2π σ x (1 /√(b² + x²) - 1 /√(a² + x²))

7 0

3 years ago

My brainly won’t load please help it’s glitching and saying “oops, something went wrong”

dmitriy555 [2]

Answer:

Try reloading the page.

Explanation:

3 0

3 years ago

Which of these is not shared by Bohr's model and the modern atomic model?

Ainat [17]

"D. Both have electrons that orbit the atomic nucleus in a similar way ." is not shared by Bohr's model and the modern atomic model.

Hope this helps,

Davinia.

5 0

3 years ago