Answer:
Work done to pull the piano upwards is 401250 J
Explanation:
Work is done against the gravity to pull the piano upwards
So here we can say that work done is

here we know that

also we know that
H = 75 m
now we have


<span>Technician a says that to prevent injuries in an auto accident, all steering columns have a break-off steering wheel. technician b says that to prevent injuries in an accident, all steering columns are now fitted with a flexible rubber tube. Both technicians are correct. The </span>vehicle manufacturers use break away steering column mounting brackets to protect the driver in an accident. The <span>vehicle manufacturers are required to use collapsible shafts in the steering column. </span>
Answer:
a. ρ
b. 
Explanation:
a. To find the density of magnetic field given use the gauss law and the equation:
,
,
Ω,
,
, 
ρ
ρ
ρ
ρ
b. The electric field can be find using the equation:




Answer:
The train's displacement is zero.
Explanation:
Given data,
The time taken by the train from NY to Washington and back is, t = 6 h 5 min
The distance between the two stations is, d = 363 km
Therefore, the total distance the train traveled is, d' = 726 km
The displacement is defined as the change in position coordinates with respect to its original position.
If the train travels from one point and returns back to the same point after some time, there is no change in the position coordinates with respect to its original position.
Hence, the train's displacement is zero.