Answer:
a) Yes because spiderman isn’t part of the system (the train), so he exerts an external force on the system, causing it to slow. The sign is negative because the train is slowing negative.
b) The train was initially moving, so it had kinetic energy, the energy of movement. There isn’t the same amount anymore because spiderman did work onto the train. Work is defined by the change of kinetic energy of the system, so the train didn’t have the same amount of that type of energy at the end.
I hope this helps! :)
Answer:
Explanation:
acceleration of test tube
= ω² R
= (2πn)² R
= 4π²n²R
n = no of rotation per second
= 3700 / 60
= 61.67
R = .10 m
acceleration
= 4π²n²R
= 4 x 3.14² x 61.67² x .10
= 14999 N Approx
Answer:
An object with 0 acceleration is accelerating in a direction that is opposite to a stated positive direction.
Explanation:
Acceleration is not always based on speeding up or slowing down (a constant speed is no acceleration at all), it's also based on direction. If you state that an object is positively accelerating when you throw it upwards, then it's negatively accelerating when it's falling even though it's velocity is increasing.
C. Three isotopes of the same element because the number of electrons and protons remain the same but the number of neutrons in the nucleus are different. This means that the isotopes have different masses to each other but the same chemical properties.
Answer:
D. x-rays
Explanation:
Lower frequency: Radio waves, microwaves and infrared have lower frequency than visible light. Shorter wavelength: Ultraviolet, x-rays and gamma rays have a shorter wavelength than visible light.
