Let the key is free falling, therefore from equation of motion
.
Take initial velocity, u=0, so
.

As velocity moves with constant velocity of 3.5 m/s, therefore we can use formula

From above substituting t,
.
Now substituting all the given values and g = 9.8 m/s^2, we get
.
Thus, the distance the boat was from the point of impact when the key was released is 10.60 m.
The answer is: 120V
Power is the rate at which energy is supplied/transformed in time:
we can write:
V ddp in Volts represents Energy/Charge i.e. energy carried by each coulomb;
I current in Amperes represents Charge/time or coulombs passing each seconds.
combining them we have:
Power = energy/time = V • 1
or
1200 = V ⋅ 10
V = 1200/10 = 120V
Answer:
D
Explanation:
We know the formula for Work to be:
W = f * d
Where W is work done
f is force
d is the distance
A)
Work = 50
Distance = 50
So, Force is:
Force = 50/50 = 1
B)
Work = 400
Distance = 80
Force = 400/80 = 5
C)
Work = 365
Distance = 73
Force = 365/73 = 5
D)
Work = 144
Distance = 16
Force = 144/16 = 9
Hence, D is the situation in which the force applied is the greatest.