Question

The velocity of a plane that travels 450.0 km due north in 3.500 hours is

12.86 km/h due north
64.25 km/h due north
128.6 km/h due north
642.8 km/h due north

Answer 1

@imqwerty

Answer 2

i got C

Answer 3

You are correct!

@imqwerty Can you confirm? :)

Answer 4

yeah thas correct

Answer 5

Why do you think it's C

Answer 6

Great! :)

Answer 7

thans, just making sure

Answer 8

i got the third one

Answer 9

Lol

Answer 10

yeah I am sorry

Answer 11

but can you guys confirm, the last one right?

Answer 12

its not c because a body can accelerate without changing its direction

for example- you can accelerate you car without changing the direction of motion

Answer 13

Acceleration depends on a change in velocity, not speed.

Answer 14

oh so a change in speed and or direction.....

Answer 15

well if direction changes then the direction of velocity also changes
and if velocity changes then certainly some acceleration is there :)

Answer 16

yes, so I am right, right? just want to make sure i get the concept

Answer 17

@imqwerty

Answer 18

okay which option did you finally chose ?

Answer 19

the middle one!

Answer 20

yes that would be correct

Answer 21

Acceleration and velocity are both vectors. The have both magnitude and direction.
Speed is a scalar with only magnitude.

Answer 22

thank you for the learning

Answer 23

np :)

Answer 24

@imqwerty

Answer 25

well the force acting here is the gravitational force of attraction

the earth pulls the rock
at the same time the little rock also pulls the earth towards it :)
but because the mass of rock is very less and of earth is too much so the displacement of earth is 0 (it doesn't moves)

Answer 26

so you are correct :)
the rock also applies pull on earth