Miswer

Which of Newton's laws of motion describes the motion of an object that has a net<br> force of ON?

algol [13]

Newton's first and second laws of motion both do, but I think the one you're looking for is: <em>The First Law of Motion</em>. That description is a little more direct.

It says that if an object is not acted on by a net external force, then it continues in "constant, uniform motion".

3 0

1 year ago

A runaway railroad car, with mass 30x10^4 kg, coasts across a level track at 2.0 m/s when it collides with a spring loaded bumpe

Natalija [7]

Answer:

0.775 m

Explanation:

As the car collides with the bumper, all the kinetic energy of the car (K) is converted into elastic potential energy of the bumper (U):

$U=K\\frac{1}{2}kx^2 = \frac{1}{2}mv^2$

where we have

$k=2\cdot 10^6 N/m$ is the spring constant of the bumper

x is the maximum compression of the bumper

$m=30\cdot 10^4 kg$ is the mass of the car

$v=2.0 m/s$ is the speed of the car

Solving for x, we find the maximum compression of the spring:

$x=\sqrt{\frac{mv^2}{k}}=\sqrt{\frac{(30\cdot 10^4 kg)(2.0 m/s)^2}{2\cdot 10^6 N/m}}=0.775 m$

8 0

2 years ago

Read 2 more answers

3. How does Earth’s rotation affect our view of stars

Elis [28]

Since we ride along with the Earth while it's doing whatever it does,
the Earth's rotation causes our eyes to constantly point in a different
direction.

If we try to keep watching one star, we have to keep changing the
direction of our eyes to keep looking at the same star.

We can't feel the Earth rotating, so our brains say that the star ... and
the sun and the moon too ... is actually moving across the sky.

5 0

2 years ago

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What is the impulse of a 3 kg object that starts from rest and moves to 20 m/s?

IrinaK [193]

Answer:

The impulse on the object is 60Ns.

Explanation:

Impulse is defined as the product of the force applied on an object and the time at which it acts. It is also the change in the momentum of a body.

F = m a

F = m( $\frac{v_{2} - v_{1} }{t}$ )

⇒ Ft = m( $v_{2}$ - $v_{1}$ )

where: F is the dorce on the object, t is the time at which it acts, m is the mass of the object, $v_{1}$ is its initialvelocity and $v_{2}$ is the final velocity of the object.

Therefore,

impulse = Ft = m( $v_{2}$ - $v_{1}$ )

From the question, m = 3kg, $v_{1}$ = 0m/s and $v_{2}$ = 20m/s.

So that,

Impulse = 3 (20 - 0)

= 3(20)

= 60Ns

The impulse on the object is 60Ns.

8 0

2 years ago

A5.0 kg TNT explosive, initially at rest, explodes into two pieces. One of the pieces weighing 2.0 kg flies off to

nordsb [41]

Answer:

v = 24 m/s, rightwards

Explanation:

Given that,

The mass of TBT explosive = 5 kg

It explodes into two pieces.

One of the pieces weighing 2.0 kg flies off to the left at 36 m/s. Let left be negative and right be positive.

The law of conservation of momentum holds here. Let v be the final speed of the remaining piece. So,

$5\times 0=2\times (-36)+3\times v\\\\-72=-3v\\\\v=24\ m/s$

So, the final speed of the remaining piece is 24 m/s and it is in the right direction.

4 0

2 years ago