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2 years ago

Integrated Science- 8th grade science

Physics

2 answers:

Kaylis [27]2 years ago

8 0

Answer:

The answer is option letter B

padilas [110]2 years ago

3 0

Answer:

A. a rigorously tested explanation

Explanation:

B. and D. are out - theories are not opinionated, they are factual
C. is out - not all theories are mathematical
A. is the best choice

You might be interested in

Identify each picture as either an inelastic collision or elastic collision

Ivan

Answer:

Inelastic collision:

A collision in which there is a loss of Kinetic Energy due to internal friction of the bodies colliding.

Characteristics of an inelastic collision:

the momentum of the system is conserved
the momentum of the system is conservedloss of kinetic energy

In a perfectly elastic collision, the two bodies that collide with each other stick together.

Elastic collision:

A collision in which the kinetic energy of the two bodies, before and after the collision, remains the same.

Characteristics of elastic collision:

the momentum of the system is conserved
no loss of kinetic energy

In everyday life, no collision is perfectly elastic.

__________________

ANSWER:

Given examples:

Two cars colliding with each other form an example of inelastic collision.

Reason:

(They lose kinetic energy and come to a stop after the collision.)

A ball bouncing after colliding with a surface is an example of elastic collision

Reason:

(a very less amount of kinetic energy is lost)

7 0

2 years ago

During an auto accident, the vehicle's air bags deploy and slow down the passengers more gently than if they had hit the windshi

vladimir2022 [97]

Answer:

At a deceleration of 60g, or 60 times the acceleration due to gravity a person will travel a distance of 0.38 m before coing to a complete stop

Explanation:

The maximum acceleration of the airbag = 60 g, and the duration of the acceleration = 36 ms or 36/1000 s or 0.036 s

To find out how far (in meters) does a person travel in coming to a complete stop in 36 ms at a constant acceleration of 60g

we write out the equation of motion thus.

S = ut + 0.5at²

wgere

S = distance to come to complete stop

u = final velocoty = 0 m/s

a = acceleration = 60g = 60 × 9.81

t = time = 36 ms

as can be seen, the above equation calls up the given variable as a function of the required variable thus

S = 0×0.036 + 0.5×60×9.81×0.036² = 0.38 m

At 60g, a person will travel a distance of 0.38 m before coing to a complete stop

7 0

3 years ago

A box slides down a 30.0° ramp with an acceleration of 1.20 m/s^2. Determine the coefficient of kinetic friction between the box

Zielflug [23.3K]

m = mass of the box

N = normal force on the box

f = kinetic frictional force on the box

a = acceleration of the box

μ = coefficient of kinetic friction

perpendicular to incline , force equation is given as

N = mg Cos30 eq-1

kinetic frictional force is given as

f = μ N

using eq-1

f = μ mg Cos30

parallel to incline , force equation is given as

mg Sin30 - f = ma

mg Sin30 - μ mg Cos30 = ma

"m" cancel out

a = g Sin30 - μ g Cos30

inserting the values

1.20 = (9.8) Sin30 - (9.8) Cos30 μ

μ = 0.44

4 0

3 years ago

The half-life of a certain radioactive substance is 12 hours. There are 19 grams present initially. a. Express the amount of su

neonofarm [45]

Answer:

(a) $N=19\times e^{-\lambda t}$

(b) 15 hours

Explanation:

half life, T = 12 hours

No = 19 g

(a) Let N be the amount remaining after time t.

Let λ be the decay constant.

$\lambda =\frac {0.6931}{T}$

The equation of radioactivity used here is given by

$N=N_{o}e^{-\lambda t}$

$N=19\times e^{-\lambda t}$

(b) N = 8 gram

Substitute the values in above equation

$\lambda =\frac {0.6931}{12}$

λ = 0.0577 per hour

So, $8=19\times e^{-0.577t}$

$e^{-0.0577t}=0.421$

Take natural log on both the sides

- 0.0577 t = - 0.865

t = 15 hours

4 0

3 years ago

PLEASE HELP ME!

PilotLPTM [1.2K]

Answer:

a) A = 3 cm, b) T = 0.4 s, f = 2.5 Hz,

2) A standing wave the displacement of the wave is canceled and only one oscillation remains

Explanation:

a) in an oscillatory movement the amplitude is the highest value of the signal in this case

A = 3 cm

b) the period of oscillation is the time it takes for the wave to repeat itself in this case

T = 0.4 s

the period is the inverse of the frequency

f = 1 /T

f = 1 /, 0.4

f = 2.5 Hz

2) a traveling wave is a wave for which as time increases the displacement increases, in the case of a transverse wave the oscillation is perpendicular to the displacement and in the case of a longitudinal wave the oscillation is in the same direction of the displacement.

A standing wave occurs when a traveling wave bounces off some object and there are two waves, one that travels in one direction and the other that travels in the opposite direction. In this case, the displacement of the wave is canceled and only one oscillation remains.

8 0

3 years ago