Which is true?

Question

A red car is loaded into spring launcher & is launched horizontally. The process is repeated with blue car of greater mass. Both times the spring is compressed the same distance.

which is true?

-the blue has greater KE
-red has greater KE
-both have same KE
-both emerge with same speed
-both have same KE and emerge with same speed

Answer 1

they DO NOT launch with the same speed. it takes more energy to launch a heavier (greater) mass. with a horizontal launch the spring exerts the same force on both cars and the KE is the same but divided differently between velocity and mass...

Answer 2

Both have the same kinetic energy.

Since the spring is compressed the same amount both times, the same amount of work has been done on each car. That means they both have the same amount of kinetic energy upon exiting the launcher.

Since the blue car has a greater mass, but the same kinetic energy, it will have a smaller speed.

Answer 3

The amount of energy put into the system has to equal the amount that comes out, so the kinetic energy of the spring is 1/2(kx^2) and is equal to the kinetic energy of the car 1/2(mv^2). The kinetic energy of the spring is the same for both vehicles since the spring constant (k) is not changed and the displacment (x) is the same. However, the velocity of the cars is different since they have different masses.

Answer 4

F = -k x

-k is the spring constant

x = the same for both cars

therefore the force is the same.

KE = 0,5*M*v^2

M1
a = F/m

change in velocity/ time = F/M

therefore they have the same KE with different speeds

Answer 5

I'd guess both have same KE...Red car traveling faster than blue car

Answer 6

Same KE

Not same speed

Answer 7

-both have same Kinetik Energy and emerge with same
speed.