Explanation:
average speed = total distance travelled / total time travelled
time to travel the first 6km: 6 / 50 = 3/25 (h)
time to travel the next 6km: 6 / 90 = 1/15 (h)
[I think there's problem in the question 'cause 900km/h sounds impossible for normal person to travel in normal condition]
The total time: 3/25 + 1/15 = 14/75 (h)
Average speed over the 12 km drive will be:

letter a because 4N to the left +3N to the right = 4N left minus 3N left as you change the direction of 3N then you also change the plus into minus. the direction will always favour to which of the direction is bigger
By definition, the mechanical advantage is the relationship that exists between the output force or load lifted and the value of the force applied.
Thus, using the definition, we have that the mechanical advantage is given by:

Therefore, the mechanical advantage of lifting the box by using a pulley is equal to 1.
Answer:
The mechanical advantage in this situation is:
Equal to 1
Energy used by the element = 6336000 j
The electrical energy is given by
E= V i t
V= voltage= 110 V
i= current=3.2 A
t= time= 5 h= 5 (3600)= 18000 s
so energy= E= 110 (3.2)(18000)
E=6336000 J
Answer:
option b
Explanation:
There is an object pulled inward in an electric field.
We have to find out of the four options given which is true.
a) The object has a neutral charge is false since when electric field pulls the object inward, there is a charge inside.
b) The object has a charge opposite that of the field, this option is correct since there will be an equal and opposite charge created by the object
c) The object has a negative charge will be correct only if the original charge was positive hence wrong
d) The object has a charge the same as that of the field is incorrect since this would be opposite the charge
So only option b is right