Question

A passenger train pulls out of the station. Couplings hold the cars together. Which of the following is true? @agent0smith

Answer 1

The tension in the coupling between the last two cars is equal to the tension between the first two cars
The tension in the coupling between the engine and the first car is greater than the tension between the last cars
The tension in the coupling between the engine and the first car is less than the tension between the last cars
The couplings in the middle of the train carry the greatest load
Since all cars are accelerating at the same rate, the force is the same in all the couplings

Answer 2

The tension in the coupling between the engine and the first car is greater than the tension between the last cars

because the front coupling is pulling the entire weight of the train, the last one only pulls the last car

Answer 3

A man applies a downward force of 15N and a horizontal force of 45N to a lawnmower. If he pushes the lawnmower 100 meters, how much work was done?

So I know the formula is
W= F x D
So would I add both forces and multiply it by 100? Or how would I do it?

Answer 4

Don't add both forces. The only force that matters is the one that's pushing in the direction it is moving

Answer 5

So only 45N would matter then?

Answer 6

Yep

Answer 7

4500 J?

Answer 8

So is power measured in watts?

Answer 9

Yes and yes

Answer 10

Gee I finally kinda understand.
If you drop a .3kg rock down a 40m well, how much potential energy does the rock lose?

This I need help with.... Is it...?
PE= m X g X h?

Answer 11

Yes

Answer 12

Gravity is 9.8 right?

Answer 13

Yes always, drill it into your mind now

Answer 14

Is it possible for it to be -?

Answer 15

Yes, sometimes you want it to be

Answer 16

Usually only when something is being thrown upward

Answer 17

So if I throw you upward you'll be -? LOL

Answer 18

:D lol no, g will be -9.8

Answer 19

Yea srry **gravity hahha

Answer 20

i got 117.6

Answer 21

I will not remind you again.

Answer 22

OMG

Answer 23

so 120 J?

Answer 24

I WILL NOT REMIND YOU AGAIN.

Answer 25

LOL STFU.
.3*9.8*40
=117.6

Answer 26

good.

Answer 27

so 120?

Answer 28

Sure why not

Answer 29

lol stooppppp you idiot

Answer 30

I'm a cop, you idiot!