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3 years ago

14

A boy pushes his 5.0 kg Thomas the Train toy from rest with a horizontal force of 5 N. What is the KE of the toy after being pus

hed 4.0 m horizontally ? What is the final speed of the toy?

1 answer:

raketka [301]3 years ago

3 0

Answer:

15 miles

Explanation:

my opinion is 15 because 15 is the most reasonable answer

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Two simple pendulum of slightly different length , are set off oscillating in step is a time of 20s has elasped , during which t

adell [148]

Answer:

Length of longer pendulum = 99.3 cm

Length of shorter pendulum = 82.2 cm

Explanation:

Since the longer pendulum undergoes 10 oscillations in 20 s, its period T = 20 s/10 = 2 s.

From T = 2π√(l/g), the length of the pendulum. l = T²g/4π²

substituting T = 2s and g = 9.8 m/s² we have

l = T²g/4π²

= (2 s)² × 9.8 m/s² ÷ 4π²

= 39.2 m ÷ 4π²

= 0.993 m

= 99.3 cm

Now, for the shorter pendulum to be in step with the longer pendulum, it must have completed some oscillations more than the longer pendulum. Let x be the number of oscillations more in t = 20 s. Let n₁ = number of oscillations of longer pendulum and n₂ = number of oscillations of longer pendulum.

So, n₂ = n₁ + x. Also n₁ = t/T₁ and n₂ = t/T₂ where T₂ = period of shorter pendulum.

t/T₂ = t/T₁ + x

1/T₂ = 1/T₁ + x (1)

Also, the T₂ = t/n₂ = t/(n₁ + x) (2)

From (1) T₂ = T₁/(T₁ + x) (3)

equating (2) and (3) we have

t/(n₁ + x) = T₁/(T₁ + x)

substituting t = 20 s and n₁ = 10 and T₁ = 2s, we have

20 s/(10 + x) = 2/(2 + x)

10/(10 + x) = 1/(2 + x)

(10 + x)/10 = (2 + x)

(10 + x) = 10(2 + x)

10 + x = 20 + 10x

collecting like terms

10x - x = 20 - 10

9x = 10

x = 10/9

x = 1.11

x ≅ 1 oscillation

substituting x into (2)

T₂ = t/n₂ = t/(n₁ + x)

= 20/(10 + 1)

= 20/11

= 1.82 s

Since length l = T²g/4π²

substituting T = 1.82 s and g = 9.8 m/s² we have

l = T²g/4π²

= (1.82 s)² × 9.8 m/s² ÷ 4π²

= 32.46 m ÷ 4π²

= 0.822 m

= 82.2 cm

6 0

3 years ago

An iron atom (Fe) has 26 protons in it. If the atom has 20 electrons in it, explain what type of charge it has and how you can t

gogolik [260]

Answer:

The iron atom has a positive charge, making it a cation.

Explanation:

The atom has a nucleus, where the protons and neutrons, which are the subatomic particles with the highest mass, are located. Practically all the mass of the atom is concentrated in the nucleus.Protons have a positive electrical charge, while neutrons have no charge.

Electrons move around the nucleus with other negatively charged particles.

An iron atom (Fe) has 26 protons and 20 electrons in it. That is, there are 6 more protons than electrons. As mentioned, protons are positively charged. So <u><em>the iron atom has a positive charge, making it a cation</em></u>.

4 0

3 years ago

A small branch is wedged under a 200 kg rock and rests on a smaller object. The smaller object is 2.0 m from the large rock and

Alexxandr [17]

Answer:

a

$F =326.7 \ N$

b

$M = 6$

Explanation:

From the question we are told that

The mass of the rock is $m_r = 200 \ kg$

The length of the small object from the rock is $d = 2 \ m$

The length of the small object from the branch $l = 12 \ m$

An image representing this lever set-up is shown on the first uploaded image

Here the small object acts as a fulcrum

The force exerted by the weight of the rock is mathematically evaluated as

$W = m_r * g$

substituting values

$W = 200 * 9.8$

$W = 1960 \ N$

So at equilibrium the sum of the moment about the fulcrum is mathematically represented as

$\sum M_f = F * cos \theta * l - W cos\theta * d = 0$

Here $\theta$ is very small so $cos\theta * l = l$

and $cos\theta * d = d$

Hence

$F * l - W * d = 0$

=> $F = \frac{W * d}{l}$

substituting values

$F = \frac{1960 * 2}{12}$

$F =326.7 \ N$

The mechanical advantage is mathematically evaluated as

$M = \frac{W}{F}$

substituting values

$M = \frac{1960}{326.7}$

$M = 6$

6 0

4 years ago

An ice skater slides in a straight line across the ice. As she passes a certain point, her velocity is 24 km/hr. Two seconds lat

gulaghasi [49]

Acceleration = (change in speed) / (time for the change)

Change in speed = (later speed) - (earlier speed) = (13 - 24) = -11 km/hr
Time for the change = 2 seconds

Acceleration = (-11 km/hr) / (2 sec)

Acceleration = -5.5 km/hr-sec (B)

5 0

3 years ago

Makala arrives late to class and misses the first few minutes of the lecture. These are the notes she takes:

lukranit [14]

Answer:

B. Quantum Mechanics

Explanation:

Quantum mechanics is the foundation of all quantum physics including quantum chemistry, quantum field theory, and quantum information science.

4 0

3 years ago

Read 2 more answers