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4 years ago

Select answer about motion and newtons law and explain why it's correct 23POINTS NEED ASAP

Physics

1 answer:

zlopas [31]4 years ago

3 0

The train would need the greatest amount of force due to weight! If you think of it, a baseball won't need much force to stop it, but if you have a heavy train, it will need excessive force to stop the train. The answer would be #3

I hope this answer helps!

Sorry if it doesn't make sense, as I don't know that much about physics! I am just thinking of what makes sense.

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In a perfectly elastic collision between two perfectly rigid objects

ipn [44]

Both the total momentum and the total kinetic energy are conserved

Explanation:

- In a collision between two or more objects, if there are no external forces acting on the system (isolated system), the total momentum of the objects is always conserved. This is called principle of conservation of momentum, and can be written as follows:

$mu+MU = mv+MV$

where

m, M are the masses of the two objects

u, U are the initial velocities of the two objects

v, V are the final velocities of the two objects

- The total kinetic energy, however, is not always conserved. In fact, we have two types of collision:

1) In a perfectly elastic collision, the total kinetic energy of the objects is conserved. This means that we can write the following equation:

$\frac{1}{2}mu^2 + \frac{1}{2}MU^2 = \frac{1}{2}mv^2+\frac{1}{2}MV^2$

2) In an inelastic collision, the total kinetic energy of the object is NOT conserved. This means that part of the total kinetic energy is "lost", converted into other forms of energy (mainly thermal energy, due to the presence of frictional forces within the system). The most extreme case is called perfectly inelastic collision, in which the two objects stick together after the collision, and there is the maximum loss of kinetic energy.

Learn more about collisions:

brainly.com/question/13966693#

brainly.com/question/6439920

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7 0

4 years ago

5.00-kg particle starts from the origin at time zero. Its velocity as a function of time is given by v =6t^2 i + 2t j where v is

otez555 [7]

The concept of derivatives and integrals allows to find the results for the questions are the motion of a particle where the speed depends on time are:

a)the position is: r = 2 t³ i + t² j

b) the position of the body on the y-axis is a parabola and on the x-axis it is a cubic function

c) The acceleration is: a = 12 t i + 2 j

d) the force is: F = 60 t i + 10 j

e) the torque is: τ = 40 t³ k^

f) tha angular momentum is: L = 4t³ - 6 t² k^

g) The kinetic energy is: K = 2 m t² (9t² +1)

h) The power is: P = 2m (36 t³ + 2t)

Kinematics studies the movement of bodies, looking for relationships between position, speed and acceleration.

a) They indicate the function of speed.

v = 6 t² i + 2t j

Ask the function of the position. The velocity is defined by the variation of the position with respect to time

v = $\frac{dr}{dt}$

dr = v dt

we substitute and integrate.

∫ dr = ∫ (6 t² i + 2t j) dt

r - 0 = $6 \frac{t^3 }{3} \ \hat i + 2 \frac{t^2}{2 \ \hat j }$

r = 2 t³ i + t² j

b) The position of the body on the y axis is a parabola and on the x axis it is a cubic function.

c) Acceleration is defined as the change in velocity with time.

$a = \frac{dv}{dt}$

a = $\frac{d}{dt} \ (6t^2 i + 2t j)$

a = 12 t i + 2 j

d) Newton's second law states that force is proportional to mass times the body's acceleration.

F = ma

F = m (12 t i + 2 j)

F = 5 12 t i + 2 j

F = 60 t i + 10 j

e) Torque is the vector product of the force and the distance to the origin.

τ = F x r

The easiest way to write these expressions is to solve for the determinant.

$\tau = \left[\begin{array}{ccc}i&j&k\\F_x&F_y&F_z\\x&y&z\end{array}\right]$

$\tau = \left[\begin{array}{ccc}i&j&k\\60t &10&0\\2t^3 &t^2&0\end{array}\right]$

τ = (60t t² - 2t³ 10) k

τ = 40 t³ k ^

f) Angular momentum

L = r x p

L =rx (mv)

L = m (rxv)

The easiest way to write these expressions is to solve for the determinant.

$\left[\begin{array}{ccc}i&j&k\\2t^3 &t^2&0\\6t^2&2t&0\end{array}\right]$

L = (4t³ - 6 t²) k

g) The kinetic energy is

K = ½ m v²

K = ½ m (6 t² i + 2t j) ²

K = m 18 t⁴ + 2t²

K = 2 m t² (9t² +1)

h) Power is work per unit time

P = $\frac{dW}{dt}$ dW / dt

The relationship between work and kinetic energy

W = ΔK

P = $2m \ \frac{d}{dt} ( 9 t^4 + t^2)$

p = 2m (36 t³ + 2t)

In conclusion with the concept of derivatives and integrals we can find the results for the questions are the motion of a particle where the speed depends on time are:

a) The position is: r = 2 t³ i + t² j

b) The position of the body on the y-axis is a parabola and on the x-axis it is a cubic function

c) The acceleration is: a = 12 t i + 2 j

d) The force is: F = 60 t i + 10 j

e) The torque is: τ = 40 t³ k^

f) The angular momentum is: L = 4t³ - 6 t² k^

g) The kinetic energy is: K = 2 m t² (9t² +1)

h) The power is: P = 2m (36 t³ + 2t)

Learn more here: brainly.com/question/11298125

8 0

2 years ago

Read 2 more answers

Why does the transition of light waves from water to air make it seem as if fish and other things in a pond are shallower then t

adell [148]

An object seen in the water will usually appear to be at a different depth than it actually is, due to the refraction of light rays as they travel from the water into the air. This tutorial explores how fish, observed from the bank of a pond or lake, appear to be closer to the surface than they really are.

5 0

3 years ago

Read 2 more answers

A source emits a sound and is represented by the red dot in this map. Four people are located around the source, and the circles

xenn [34]

Answer:

Explanation:

When a sound is produced by a stationary point source , moving waves are produced around it in circles consisting of compression and rarefaction . These compression and rarefaction are mutually equidistant. But when the source moves in a particular direction , waves get compressed in that direction . If in a distance of V , n number of waves are formed , in case of moving source , same no of waves will lie in V - v distance in the direction of motion. . Here V is velocity of sound , v is velocity of source and n is no of waves being produced per second. So we see that distance between two consecutive waves becomes smaller . Or , waves get compressed . In this region frequency becomes greater.

A is standing left of source and source is moving towards left , hence A. will hear highest pitch or greatest frequency.

4 0

3 years ago

When you see Marjorie, she is swinging a bucket of water around in a circle. The speed of the bucket of water does not change as

ser-zykov [4K]

Answer:A

Explanation:

Since the bucket of water is constantly in motion it implies a force must be acting on it which allows it to change its Position constantly.

A constant gravity Force must be acting on water . In addition to gravity force a centripetal force must be acting on the water inside the bucket.

Bucket must move with certain velocity in order to avoid spilling of water.

4 0

4 years ago