4.how does the kinectic energy of a 10,000-kg train traveling at a speed of 10 m/s compare with that of a 2,600-kg compact car traveling twice as fast?

A.the train has less kinectic energy than the car.

B.the train has more kinectic energy than the car.(I PICK THIS)

C.the train has the same kinectic energy as the car.

Now really, I have replied three times now. Yes

http://www.jiskha.com/display.cgi?id=1391014223

Oh sorry, slightly different, train going v

for train
(1/2) m v^2 = 5,000 * 10^2

for car

(1/2) m v^2 = 1300 * 4 * 10^2
= 5,200 * 10^2

so now it is the car number A

The answer to the test is:

1.C
2.B
3.C
4.A
I have done this test. These answers are correct.

You are welcome.

To compare the kinetic energy of the train and the car, we can use the formula for kinetic energy: KE = (1/2)mv^2, where KE is the kinetic energy, m is the mass, and v is the velocity.

For the train:
Mass (m) = 10,000 kg
Velocity (v) = 10 m/s
Kinetic energy (KE) = (1/2) * 10,000 kg * (10 m/s)^2 = 500,000 J

For the car:
Mass (m) = 2,600 kg
Velocity (v) = twice as fast as 10 m/s = 2 * 10 m/s = 20 m/s
Kinetic energy (KE) = (1/2) * 2,600 kg * (20 m/s)^2 = 520,000 J

Therefore, the kinetic energy of the train is 500,000 J and the kinetic energy of the car is 520,000 J. Since the kinetic energy of the car is greater, the correct answer is B. The train has more kinetic energy than the car.