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2 years ago

When a bicycle coasts uphill, it moves slower and slower as it climbs. Why?

Physics

2 answers:

astra-53 [7]2 years ago

6 0

Letter B because it is gaining more potential energy as it SLOWLY climbs up the hill.

the less motion the more potential energy there is

Elenna [48]2 years ago

5 0

Answer:

B. Its potential energy is transforming into kinetic energy.

Explanation:

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Explain why materials such as plastic foam, feathers, and fur are poor conductors of heat.

Firlakuza [10]

The atoms of some materials have no free electrons in their outer orbits. These electrons are busy doing other jobs, like being shared in the orbits of two adjacent atoms. They are so closely held that it is very difficult to pull them away. Most compounds of carbon and hydrogen are like this.

<span>Plastics, whose molecules are made from long combinations of carbon and hydrogen atoms, have few or no free electrons. This means that plastics are poor conductors of electricity (and they are also poor conductors of heat). hope that helped.</span>

7 0

2 years ago

A human being can be electrocuted if a current as small as 55 mA passes near the heart. An electrician working with sweaty hands

evablogger [386]

Answer:

The lethal voltage for the electrician under those conditions is 126.5 V.

Explanation:

To discover what is the lethal voltage to the electrician we need to find out what is the voltage that produces 55 mA = 0.055 A when across a resistance of 2300 Ohms (Electrician's body resistancy). For that we'll use Ohm's Law wich is expressed by the following equation:

V = i*R

Where V is the voltage we want to find out, i is the current wich is lethal to the electrician and R is his body resistance. By applying the given values we have:

V = 0.055*2300 = 126.5 V.

The lethal voltage for the electrician under those conditions is 126.5 V.

4 0

2 years ago

Read 2 more answers

If a moving car speeds up until it is going twice as fast, how much kinetic energy doe s it have compared with its initial kinet

dezoksy [38]

The kinetic energy of an object of mass m and velocity v is given by
$K= \frac{1}{2} mv^2$

Let's call $v_i$ the initial speed of the car, so that its initial kinetic energy is
$K_i = \frac{1}{2} mv_i^2$
where m is the mass of the car.

The problem says that the car speeds up until its velocity is twice the original one, so
$v_f = 2 v_i$
and by using the new velocity we can calculate the final kinetic energy of the car
$K_f = \frac{1}{2} mv_f^2 = \frac{1}{2}m (2 v_i)^2 = 4 ( \frac{1}{2} mv_i^2)=4 K_i$
so, if the velocity of the car is doubled, the new kinetic energy is 4 times the initial kinetic energy.

6 0

2 years ago

A car accelerates from rest for 8.0 s, and reaches a speed of 66 m/s. How far will the

PSYCHO15rus [73]

Answer: C

Explanation:

Find the acceleration using this kinematic equation:

$v_f=v_i+at\\66=0+a*8\\a=8.25m/s^2$

Now use this kinematic equation to find the displacement:

$v_f^2=v_i^2+2a*d\\66^2=0^2+2(8.25)d\\4356=16.5d\\d=264m$

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3 years ago

In the demonstration by Cal’s teacher, the string represents the force that keeps the planet in orbit. Which statement BEST desc

Flauer [41]

Answer:

yessyes

Explanation:

yes

5 0

2 years ago