The potential energy of the block is given by:
V = m*g*h
m mass
g = 9.81m/s²
h height
The potential energy of a spring is given by:
V = 0.5 * k * x²
k spring constant
x compression of the spring
If the block starts from rest it has potential energy, but no kinetic energy. As it slides down the incline potential energy is converted into kinetic energy. When the block hits the spring the kinetic energy is converted into spring's potential energy. If the spring is fully compressed and the block is at rest again, the block has transferred all its energy into the spring. No energy is lost. So we can write:
m * g * h = 0.5 * k * x²
m = 0.5 kg
g = 9.81 m/s²
h = 2.5m * sin 37° = 1,5 m
x = 0,6 m
Solve for k.
k = 2 * m * g * h / x² = 40.8 N/m
Answer:
The forces acting on the pen which is still on the table can have two forces acting on them. The forces are gravitational force and the equal and opposite force to the gravitational forces.
The equal and opposite forces that is applied on the pen keeps the pen still on the table.
So, the statement that no force is applied on the pen which is kept still on the table is wrong as two forces are applied on the pen.
As both the forces are equal and opposite so it is cancelled and is still.
The energy that transforms into kinetic energy is the Potential Energy. It happens that objects can store energy as a result of its position. Image for example a slingshot. When you stretch the slingshot, it stores energy, this energy would be the energy you used to stretch the slingshot, the material aborbs it and then release to throw the projectile.
Now, on earth and everywhere in the universe where you are close to an object with mass, it exists a force called gravity that attracts you towards that object. Every object that has mass exercises gravitational attration towards the other objects. It just happens that Earth is has so much mass that its gravitational pull is way stronger that the gravitational pull of another object on its surface. This means things will tend to be as close as earth as possible, and in order to move something away from earth, you will have to perform a force in the opposite direction to Earth and, therefore, consume energy. This energy will be store as potential energy, and when you drop the object, the potential energy will be the energy that will transform to kinetic energy.
<span>Th find the average speed of a trip we need to dived the total distance by the total time.
Let's find the total distance d.
d = (300 mi/h)(2.00 h) + 750 miles
d = 600 miles + 750 miles
d = 1350 miles
The total distance is 1350 miles
Let's find the total time t.
t = 2.00 hours + (750 mi / 250 mi/h)
t = 2.00 hours + 3.00 hours
t = 5.00 hours
The total time of the trip is 5.00 hours.
We can find the average speed.
d / t = 1350 miles / 5.00 hours
d / t = 270 miles/ hour
The average speed of the trip is 270 mi/h
(Note that the direction does not matter when we find the average speed.)</span>
Answer:
Explained below
Explanation:
A) Newton's first law of motion states that an object will remain at rest or continue in its current state of motion except it is acted upon by another force.
Now using this law, when you jump off the ground, the earth will move a tiny bit and accelerate due to the force applied by the jumping.
B) Newton's 2nd law states that the acceleration of a system is directly proportional to the net external force acting on that system, is in the same direction with it and also inversely proportional to the mass.
In this case, when one jumps, an external force is exerted on the earth and we are told it is directly proportional to the acceleration of the system which in this case it's the earth, then it means that there is some motion by the earth even though you didn't see it move.
C) Newton's third law of motion states that to every action, there is an equal and opposite reaction.
In this case the motion of the jumper will lead to an equal and opposite reaction of the earth.
