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3 years ago

I need help with these questions.

Physics

1 answer:

strojnjashka [21]3 years ago

4 0

I'll go ahead and answer the ones here without an answer. For reference, the half-life formula is final amount = original amount(1/2)^(time/half-life)

4) 12.5g

x = 100(1/2)^(63/21)

5) 50g

3.125 = x(1/2)^(0.1/0.025)

6) 500g

x = 4000(1/2)^(525/175)

7) 0.24g

0.06 = x(1/2)^(11430/5730)

8) 125g

x = 1000(1/2)^(17100/5700)

Hope this helps! :)

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8. A 2 kg flower pot weighing 20 N falls from a window ledge.

Alina [70]

The force of the air resistance is 4 N.

The given parameters;

mass of the flower pot, m = 2 kg

weight of the flower pot, W = 20 N

Let the air resistance = F

Apply Newton's second law of motion to determine the force of the air resistance acting upward to oppose the motion of the pot falling downwards.

$\Sigma F = ma\\\\W - F = ma\\\\a = \frac{W - F}{m} \\\\8 = \frac{20 - F}{2} \\\\20 - F = 16\\\\F = 20 - 16\\\\F = 4 \ N$

Thus, the force of the air resistance is 4 N.

Learn more here: brainly.com/question/19887955

8 0

3 years ago

The mathematical symbol for period is O A. A O B. v OC. T O D. f

Advocard [28]

Answer: C. T

Explanation:

Period is a unit of time; and in the context of waves or oscillations it is defined as "the time elapsed between two equivalent points on the wave or oscillation".

It is important to note Period (denoted by $T$ ) is one of the most important factors (along with the amplitude, frequency and velocity) to describe and characterize a wave.

In addition, Period has an inverse relation with the frequency $f$ , this means that if we are given the frequency of a wave, we can inmediatly know its Period.

3 0

3 years ago

Ned tightens a bolt in his car engine by exerting 15 N of force on his wrench at a distance of 0.45m from the fulcrum. How much

____ [38]

Answer:

$T = 6.75\,N\cdot m$

Explanation:

Vectorially speaking, torque is the cross product between force and distance from fulcrum. Its magnitude is equal to the following expression:

$T = F\cdot r \cdot \sin \theta$

$T = F_{\bot} \cdot r$

Let assume that force is perpendicular to the distance from the fulcrum. So, the torque needed to turn the bolt is:

$T = (15\,N)\cdot (0.45\,m)$

$T = 6.75\,N\cdot m$

8 0

4 years ago

Brutus, a champion weight lifter, raises 220 kg a distance of 3.10 m. (a) how much work is done by brutus lifting the weights? j

Nana76 [90]

A) work = force * distance
mass is not a force, weight is, so we have to find the weight of the block.
Weight = mg
Weight = (220kg)(9.8)
Weight = 2156N
Work = 2156N * 3.10m
work = 6683.6J
b) Since he is holding the weights, it's not moving, therefore, he doesn't do any work
c) The answer is still the same amount of work when he lifted them.
d) The answer is no since when he let go the weight, he doesn't apply any force to the weight.
e) P = work/time
P = 6683.6J / 2.1s
P = 3182.67 watts

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3 years ago

An object moving on a horizontal, frictionless surface makes a glancing collision with another object initially at rest on the s

Eddi Din [679]

Answer:

The correct answer is option 'a' 'The momentum is always conserved while as the kinetic energy may be conserved'

Explanation:

The conservation of momentum is a basic principle in nature which is always valid in an collision between 'n' number of objects if there are no external forces on the system. It is valid for both the cases weather the collision is head on or glancing or weather the object is elastic or inelastic.

The energy is only conserved in a collision that occurs on a friction less surface and the objects are purely elastic. Since in the given question it is mentioned that only the surface is friction less and no information is provided regarding the nature of the objects weather they are elastic or not hence we cannot conclusively come to any conclusion regarding the conservation of kinetic energy as the objects may be inelastic.

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4 years ago