Answer:

Explanation:
Take sum of torques at the point the step touches the wheel, that eliminates two torques
Σ
Since we are looking for when the wheel just starts to rise up N-> 0 so no torque due to normal force

The perpendicular lever arm for the F force is R-h

And the T of gravity according to the image

Σ





I think your answer would be (D) microscope with a video camera
Hope i helped!
Answer:
It’s 7 hours
Explanation:
You have to use the formula your teacher has given to you plug in the numbers then solve be sure to use a calculator made for physics it helps a lot :)
Answer:

Explanation:
When teacher falls into the cliff then she shout for Help at the same time
so here we know that sound will go down and reflect back up
so here in 3 s distance traveled by the sound



now in the same time the distance that teacher will fall down is given as



now total distance traveled by teacher and sound in 3 s


this total distance must be equal to twice the height of the cliff

