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2 years ago

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Compared with a car moving at some original speed, how much work must the brakes of a car supply to stop a car that is moving tw

ice as fast.

1 answer:

vovangra [49]2 years ago

8 0

Answer:

Compared with a car moving at some original speed, four times work must the brakes of a car supply to stop a car that is moving twice as fast. Stopping distance should also be four times.

Explanation:

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A light rope is attached to a block with mass 3.60 kg that rests on a frictionless, horizontal surface. The horizontal rope pass

Readme [11.4K]

Answer and Explanation:

(a) The fre-body diagrams for each block is shown below. In the block of mass 3.60 kg, there are 3 forces acting on it: horizontal force due to the rope ( $F_{t}$ ), vertical gravitational force ( $F_{g}$ ) and vertical normal force ( $F_{n}$ ), due to the surface. Since there is no vertical movement, $F_{g}$ and $F_{n}$ cancels it out. So, for this block, net force is horizontal due to the rope $F_{t}$ .

The block of mass m is hanging from the pulley, so there is the force of the rope ( $F_{t}$ ) and the gravitational force ( $F_{g}$ ). Both are vertical, because there is no surface "holding" block m.

(b) Since both blocks are attached to each other, the acceleration will be the same. To calculate it, we use the Second Law of Motion:

$F_{r}=m.a$

$a=\frac{F_{r}}{m}$

$a=\frac{18.8}{3.6}$

a = 5.22

The acceleration of either block is 5.22 m/s².

(c) Block m has 2 forces acting on it: tension and gravitational force. Gravitational force is the force of attraction the Earth does over an object. It is calculated as the product of mass and gravitational acceleration, which has magnitude g = 9.8 m/s².

Suppose positive referential is going up. To determine mass:

$F_{r}=m.a$

$F_{t}-F_{g}=m.a$

$F_{t}-m.g=m.a$

$18.8-9.8m=5.22m$

$15.02m=18.8$

m = 1.25

Block m has 1.25 kg.

(d) Gravitational force is also called weight. So, as described above: $F_{g}=m.g$ .

The weight for the hanging block is

$F_{g}=1.25*9.8$

$F_{g}=$ 12.25 N

Comparing tension and weight:

$\frac{12.25}{18.8}$ ≈ 0.65

We can see that, weight of the hanging block is almost 0.65 times smaller than the tension on the rope.

4 0

3 years ago

During which time does Jamal have the greatest momentum?

Yuliya22 [10]

Answer:

Momentum Packet Answer KEY - Science Online

YOU WILL SEE THE PDF

4 0

2 years ago

What happens when you change the number of electrons in an atom

aalyn [17]

<h2>Answer: It becomes an Ion </h2>

When an atom has gained or lost electrons (negative charge), it becomes an ion.

In this sense:

<h2>Ions are atoms that have <u>gained or lost</u> electrons in their electronic cortex. </h2><h2> </h2>

If a neutral atom <u>loses electrons</u>, it remains with an excess of positive charge and transforms into a positive ion or <u>cation</u>, whereas if a neutral atom <u>gains electrons</u>, it acquires an excess of negative charge and transforms into a negative ion or <u>anion</u>.

It is then how ions form bonds with other atoms differently depending on the number of electrons they have.

8 0

3 years ago

When point charges q = +8.4 uC and q2 = +5.6 uC are brought near each other, each experiences a repulsive force of magnitude 0.6

Stella [2.4K]

Answer:

it is separated by 80 cm distance

Explanation:

As per Coulombs law we know that force between two point charges is given by

$F = \frac{kq_1q_2}{r^2}$

here we know that

$q_1 = +8.4\mu C$

$q_2 = +5.6 \mu C$

force between two charges is given as

$F = 0.66 N$

now we have

$F = \frac{kq_1q_2}{r^2}$

$0.66 = \frac{(9\times 10^9)(8.4 \mu C)(5.6 \mu C)}{r^2}$

$r = 0.8 m$

so it is separated by 80 cm distance

3 0

3 years ago

Read 2 more answers

A pie is cooked in an oven at 200 °C. The aluminium film that ckvered the pie can be touched soon after it is removed while the

GREYUIT [131]

Answer and Explanation:

The aluminum is more productive in the absorption and heat transfer to other particles. It instantly converts heat absorbed from the environment into the atmosphere when removed from the oven, enabling us to operate with it faster than the pie that takes much longer to convert heat to the environment.

So this is the reason for pie to be the dangerously hot

8 0

3 years ago