A) A block of mass, m, is pushed up against a spring, compressing it a distance x, and is then released. The spring projects the block along a frictionless horizontal surface, giving the block a speed v. The same spring projects a second block of mass 4m, giving it a speed 3v. What distance was the spring compressed in the second case?B) Initially a body moves in one direction and has kinetic energy K. Then it moves in the opposite direction with three times its initial speed. What is the kinetic energy now?

Answers

Answer 1
Answer:

a)

KE=1/2mv^2

F= -kx

KE= -kx

-kx= 1/2mv^2

when u quadruple the m, the x also quadruples. when the speed is multiplied by 3, since it is v^2, the x is multiplied by 3^2 , which is 9

so distance the spring compressed is x×4×9= 36x

b) using the KE formular too,

when the v is tripled, since formula is v^2, the resulting KE will be multiplied by 3^2, so KE now= 9K


Related Questions

Which of the following is the best example of uniform circular motion? A.The motion of the second hand on a clock B.A child swinging on a park swing C.A golf ball after it has been hit off the tee D.A skier curving back and forth across a wide slope
Diffraction patterns are due to
When Earth and the Moon are separated by adistance of 3.84 × 10^8 meters, the magnitude ofthe gravitational force of attraction betweenthem is 2.0 × 10^20 newtons. What would be themagnitude of this gravitational force of attractionif Earth and the Moon were separated by adistance of 1.92 × 10^8 meters?(1) 5.0 × 10^19 N (3) 4.0 × 10^20 N(2) 2.0 × 10^20 N (4) 8.0 × 10^20 N
What fundamental force is responsible for the settling of Earth's layers?
an athlete running 2.6m/ increases his velocity to 3.7m/s in 2.7s. what is the acceleration of the runner

In a titration, the point where is indicator changes color and stays that way is the?

Answers

It is the end point of a reaction

The point on a graph where X and Y values meet is called A. the axis.
B. the origin.
C. the starting line.
D. an intersection point.

Answers

The point where x and y values meet is called the origin.

the point where they meet at is called the origin

Which of the following is NOT an example of work?a. a windmill turning in the wind
b. a person sliding a box across the floor
c. a metal bar bracing a leaning brick wall
d. an air bag deploying in an automobile wreck

Answers

Work  =  (force) · (distance)

a).  The wind does work on the windmill.

b).  The person does work on the box.

c).  The metal bar exerts force on the leaning wall,
but nothing moves, so there's no work done.

d).  The explosive inflator does work on the airbag, and very soon
after that, the driver and passengers do work on it too.

Complete the passage to describe wave interaction of diffracted waves.Diffracted waves of light interact with other waves and interference occurs. When the interference is constructive, this is shown as a

band on the screen. When the interference is destructive, this is shown as a

band on the screen.

Answers

Answer: When the interference is constructive, this is shown as a bright band on the screen. When the interference is destructive, this is shown as a dark band on the screen.

Explanation: edge 2021

Answer:Bright and Dark

Explanation:

A boat loaded with a barrel of water floats in a swimming pool. When the water in the barrel is poured overboard, the swimming pool level will _____.Question 6 options:

fall

remain unchanged

rise

Answers

Answer: Remain unchanged

Explanation:

The boat with water barrel overboard floats in swimming pool when weight of the water displaced by the boat is equal to the buoyant force acting on the boat.

When the water in the barrel is poured overboard, the level of the swimming pool level would remain unchanged as the weight of the boat  with the water and barrel would remain unchanged ( as the density and volume of the whole system remains same) and hence, the weight of the water (of the swimming pool) displaced by the boat would remain same.

A boat loaded with a barrel of water floats in a swimming pool. When the water in the barrel is poured overboard, the swimming pool level will remain unchanged.

The copper wire and bulb is connected in a series with 220 V electric supply. Why only an electric bulb glows where as the copper wire remains the same.Give REASON to support the answer.

Answers

-- In a series circuit, the current ( I ) is the same at every point.

-- The power dissipated by any section of the circuit is I² x Resistance.

-- The wire has very low resistance, so I²R is very low dissipated power.

-- The filament in the bulb has most all of the resistance in the circuit,
so it dissipates virtually all the power of the circuit, and certainly much
more than the wires do.