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4 years ago

Jenny wanted to test whether worms prefer light or darkness best. After

Physics

1 answer:

myrzilka [38]4 years ago

3 0

Answer:

True

Explanation:

An independent variable is the variable that is changed or controlled in a scientific experiment to test the effects on the dependent variable. You are changing light or dark

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Pam, wearing a rocket pack, stands on frictionless ice. She has a mass of 49 kg. The rocket supplies a constant force for 22.0 m

ss7ja [257]

Answer:

Magnitude of the force is 4350N

Explanation:

As the woman accelerates at a distance of 22 m to go from rest to 62.5 m / s, we can use the kinematics to find the acceleration

v² = v₀² + 2 a x

v₀ = 0

a = v² / 2x

a = 62.5²/(2 × 22)

a = 88.78m/s²

the time you need to get this speed

v = v₀ + a t

t = v / a

t = 62.5 / 88.78

t = 0.704s

Let's caculate the magnitude of the force

F = ma

= 49 × 88.78

= 4350.22

≅ 4350N

Magnitude of the force is 4350N

t = 1,025 s

a = 55.43 m / s²

4 0

3 years ago

S.I. Units Ampere is use for what?

lawyer [7]

The ampere (symbol: A) is the SI base unit of electric current equal to one coulomb per second.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross section, and placed 1 meter apart in vacuum, would produce between these conductors a force equal to 2 times 10–7 newton per meter of length.

Electric current is the time rate of change or displacement of electric charge.

One ampere represents the rate of 1 coulomb of charge per second.

The ampere is defined first (it is a base unit, along with the meter, the second, and the kilogram), without reference to the quantity of charge.

The unit of charge, the coulomb, is defined to be the amount of charge displaced by a one ampere current in the time of one second.

This is your answer friend. Hope it helps you.

3 0

3 years ago

Which of the following statements about neurons are NOT true?

emmasim [6.3K]

Answer:

The correct answers to the question are

The following statements about neurons are NOT true

A. The resting membrane potential is generally in the range of -40 mv to -75 mv.

C. Neurons repolarize by opening chloride channels on the membrane.

D. An action potential can occur when the neuron's sodium gates open.

Explanation:

A. The resting membrane potential is generally in the range of -40 mv to -75 mv.

Not true the resting potential for neurons range from -70 to -80 mv

B. Maintaining resting membrane potential requires the use of energy from ATP True

The potential of the membrane arises from the splitting of potassium ions from the intracellular anions by agents powered by ATP

C. Neurons repolarize by opening chloride channels on the membrane

Not True

Repolarization occurs by the outward transit of the positively charged K⁺ from the cell

D. An action potential can occur when the neuron's sodium gates open.

Not True

An action potential takes place once the neuron transmits information along an axon. An action potential results when different ions pass through the membrane of the neuron

5 0

3 years ago

Two charged spheres are 20cm apart and exert an attractive force of 6x10^-9 N on each other. What will be the force of attractio

Travka [436]

The force of attraction between 2 charged spheres can be explained by Coulomb's law,
It states the force of attraction is directly proportional to the magnitudes of the charges and inversely proportional to the square of the distance between the charges.

/ $F = \frac{k q_{1} q_{2} }{ r^{2} }$
where F - force of attraction/repulsion
q₁ and q₂ - charges of the 2 spheres
k - Coulomb's law constant
r - distance between the spheres

In the question given, the charges of the spheres remain constant in both instances, only distance changes. Therefore (kq₁q₂) = c which is a constant
then F = c / r²
first instance
6 x 10⁻⁹ N = c/ (20 cm)² ---1)
F = c/(10 cm)² --- 2)
2) / 1)
$\frac{F}{6* 10^{-9} } = \frac{400}{100}$
F = 6 x 10⁻⁹ x 4
F = 2.4 x 10⁻⁸ N

8 0

3 years ago

The 49-g arrow is launched so that it hits and embeds in a 1.45 kg block. The block hangs from strings. After the arrow joins th

Dimas [21]

Answer:

the initial speed of the arrow before joining the block is 89.85 m/s

Explanation:

Given;

mass of the arrow, m₁ = 49 g = 0.049 kg

mass of block, m₂ = 1.45 kg

height reached by the arrow and the block, h = 0.44 m

The gravitational potential energy of the block and arrow system;

P.E = mgh

P.E = (1.45 + 0.049) x 9.8 x 0.44

P.E = 6.464 J

The final velocity of the system after collision is calculated as;

K.E = ¹/₂mv²

6.464 = ¹/₂(1.45 + 0.049)v²

6.464 = 0.7495v²

v² = 6.464 / 0.7495

v² = 8.6244

v = √8.6244

v = 2.937 m/s

Apply principle of conservation of linear momentum to determine the initial speed of the arrow;

$P_{initial} = P_{final}\\\\mv_{arrow} + mv_{block} = (m_1 + m_2)V\\\\0.049(v) + 1.45(0) = (0.049 + 1.45)2.937\\\\0.049v = 4.4026\\\\v = \frac{4.4026}{0.049} \\\\v = 89.85 \ m/s$

Therefore, the initial speed of the arrow before joining the block is 89.85 m/s

4 0

3 years ago