A 2-kg toy car accelerates from 0 to 5 m/s2. It

You are working on charge-storage devices for a research center. Your goal is to store as much charge on a given device as possi

zheka24 [161]

Answer:

Part A the answer is the dielectric constant.

Part B Mica- mylar- paper- quartz

Explanation:

The capacity of a capacitor is given by

C = ε ε₀ A / d

Where the dielectric constant (ε) is the value of the material between the plates of the capacitor, we see that as if value increases the capacity also increases.

Another magnitude that we must take into account that the maximum working voltage, the greater the safer is the capacitor

the flexibility of the material must also be taken into account

Part A the answer is the dielectric constant.

Pate B order the materials from best to worst

Mica. The best ever

Mylar Flexible

Paper Low capacity, low working voltage, flexible

Quartz high dielectric, but brittle

8 0

2 years ago

On average, both arms and hands together account for 13% of a person's mass, while the head is 7.0% and the trunk and legs accou

BabaBlast [244]

Answer:

176.38 rpm

Explanation:

mass percentage of arms and legs = 13%

mass percentage of legs and trunk = 80%

mass percentage of head = 7%

Total mass of the skater = 74.0 kg

length of arms = 70 cm = 0.7 m

height of skater = 1.8 m

diameter of trunk = 35 cm = 0.35 m

Initial angular momentum = 68 rpm

We assume:

The spinning skater with her arms outstretched as a vertical cylinder (head, trunk, and legs) with two solid uniform rods (arms and hands) extended horizontally.
friction between the skater and the ice is negligible.

We split her body into two systems, the spinning hands as spinning rods

1. Each rod has moment of inertia = $\frac{1}{3} mL^{2}$

mass m of the arms is 13% of 74 kg = 0.13 x 74 = 9.62 kg

mass of each side will be assumed to be 9.62/2 = 4.81 kg

L = length of each arm

therefore,

I = $\frac{1}{3}$ x 4.81 x $0.7^{2}$ = 0.79 kg-m for each arm

2. Her body as a cylinder has moment of inertia = $\frac{1}{2} mr^{2}$

r = radius of her body = diameter/2 = 0.35/2 = 0.175 m

mass of body trunk = (80% + 7%) of 74 kg = 0.87 x 74 = 64.38 kg

I = $\frac{1}{2}$ x 64.38 x $0.175^{2}$ = 0.99 kg-m

We consider each case

case 1: Body spinning with arm outstretched

Total moment of inertia = sum of moments of inertia of both arms and moment of inertia of body trunk

I = (0.79 x 2) + 0.99 = 2.57 kg-m

angular momentum = Iω

where ω = angular speed = 68.0 rpm = $\frac{2\pi }{60}$ x 68 = 7.12 rad/s

angular momentum = 2.57 x 7.12 = 18.29 kg-rad/m-s

case 2: Arms pulled down parallel to trunk

The momentum of inertia will be due to her body trunk alone which is 0.91 kg-m

angular momentum = Iω

= 0.99 x ω = 0.91ω

according to conservation of angular momentum, both angular momentum must be equal, therefore,

18.29 = 0.99ω

ω = 18.29/0.99 = 18.47 rad/s

18.47 ÷ $\frac{2\pi }{60}$ = 176.38 rpm

7 0

2 years ago

A kinesin that is transporting a secretory vesicle uses approximately 80 ATP molecules/s. Each ATP provides a kinesin molecule w

Firdavs [7]

Answer:

The force is $F = 8*10^{-12} \ N$

Explanation:

From the question we are told that

The rate at which ATP molecules are used is $R = 80 ATP/ s$

The energy provided by a single ATP is $E_{ATP} = 0.8 * 10^{-19} J$

The velocity of the kinesin is $v = 800 nm/s = 800*10^{-9} m/s$

The power provided by the ATP in one second is mathematically represented as

$P = E_{ATP} * R$

substituting values

$P = 80 * 0.8*10^{-19 }$

$P = 6.4 *10^{-18}J/s$

Now this power is mathematically represented as

$P = F * v$

Where F is the force the kinesin is exerting

Thus

$F = \frac{P}{v}$

substituting values

$F = \frac{6.4*0^{-18}}{800 *10^{-9}}$

$F = 8*10^{-12} \ N$

7 0

2 years ago

What is the mass of a large dog that weighs 441 newtons

PtichkaEL [24]

Weight, w = mg. g ≈ 9.8 m/s². m = mass in kg. w is weight in N

441 N = m* 9.8

9.8m = 441

m = 441/9.8

m = 45 kg.

Mass of the dog is = 45 kg

5 0

2 years ago

A badger is trying to cross the street. Its velocity vvv as a function of time ttt is given in the graph below where rightwards

Mrrafil [7]

Answer: -2.5

Explanation:

1/2(-5)= -2.5

-2.5(1)= -2.5

Got it right in Khan Academy. You’re welcome.

5 0

2 years ago