How much potential energy does a 20-kg barrel have when it is in the truck whose floor is 5.0 m above the ground? P.E. = J

AveGali [126]

For no.4 is what seismologists use two main devices to measure an earthquake: a seismograph and aseismoscope. The seismographis an instrument that measures seismic waves caused by an earthquake. The seismographhas three main devices, theRichter Magnitude Scale, theModified Mercalli Intensity Scale, and the Moment-Magnitude Scale.

5 0

3 years ago

At one instant of time a rocket is traveling in outer space at 2500m/s and is exhausting fuel at a rate of 100 kg/s. If the spee

lawyer [7]

Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system. Mathematically can be written as,

$T = v\frac{dm}{dt}$

Here,

v = speed of the exhaust gases measured relative to the rocket.

$\frac{dm}{dt}$ = Rate of change of mass with respect to time

Our values are given as,

$v = 1500m/s$

$\frac{dm}{dt} = 100kg/s$

Replacing we have that

$T = 1500*100$

$\therefore T = 1.5*10^5N$

7 0

3 years ago

Plz help The momentum of a baseball changes dramatically when struck by a bat.Momentum of the ball is not conserved. The best ex

Luda [366]

Answer:

When the bat hits the ball, it exerts some force on the ball. Just think about a home run hitter hitting a stationary ball. How far do you think it will go? Will it go more than 400 ft.? Probably not. While the kinetic energy transferred from the bat to the ball accounts for some energy of the ball, it does not account for all. Where is the mysterious energy coming from?

The answer is conservation of momentum. I just said momentum is conserved but how do I know that? I know that because of Newton's 2nd law: F=ma (Force equals mass times acceleration)

Conservation of momentum means that the harder you throw you, the harder the ball will bounce back at you. That is the reason it is easier to hit a home run on a fast ball than a curveball.

Conservation of momentum also means that the bat can transfer some of its momentum to the ball. This is why it is better to use a heavier bat if you swing just as fast. The momentum is the product of the mass and velocity, so to make it easier to understand;

a heavier bat swung at the same speed as a lighter bat will have more momentum.

8 0

3 years ago

a 200 kg crate is pushed horizontally with a force of 700 N. If the coefficient of friction is 0.2 calculate the acceleration of

Crazy boy [7]

Answer:

$a=1.54\ m/s^2$

Explanation:

<u>Net Force</u>

The Second Newton's law states that an object acquires acceleration when an external unbalanced net force is applied to it.

That acceleration is proportional to the net force and inversely proportional to the mass of the object.

It can be expressed with the formula:

$\displaystyle a=\frac{F_n}{m}$

Where

Fn = Net force

m = mass

The m=200 kg crate is pushed horizontally with a force Fa=700 N. The friction force opposes motion and a horizontal net force appears causing the acceleration.

The forces on the vertical direction are in balance since the crate does not accelerate in that direction, thus the weight and the normal force are equal:

N = W = mg

The friction force can be calculated by using the coefficient of friction μ:

$F_r=\mu N$