zybooks One AA battery in a flashlight stores 9400 J. The three LED flashlight bulbs consume 0.5 W. How many hours will the flas
1 answer:
Answer:
The time for which the flashlight last is 5.23 hours.
Explanation:
Given that,
One AA battery in a flashlight stores 9400 J, E = 9400 J
Power consumed by the LED flashlight bulbs, P = 0.5 W
We need to find the time for which the flashlight last. The power of a device is given by the energy stored per unit time as :
t = 18800 seconds
or
Since, 1 hour = 3600 seconds
t = 5.23 hours
So, the time for which the flashlight last is 5.23 hours. Hence, this is the required solution.
You might be interested in
Answer:
# of Snickers bars 2
Explanation:
Power output= 0.30 HP
=0.3*746
= 0.30 HP (746 W=1.00 HP)
= 224 W
time required 2 h 49 m = 10140 seconds
Since power is work divided by time, then work is:
Work done by the jet = P*t
= 224 *(10140)
= 2.3 MJ (2.3 x J)
Converting MJ to Cal
2.3 MJ=549 Cal
# of Snickers bars = 549 Cal / 280 Cal
= 2.0 bars (rounded from 1.96)
Answer:
The maximum height the box will reach is 1.72 m
Explanation:
F = k·x
Where
F = Force of the spring
k = The spring constant = 300 N/m
x = Spring compression or stretch = 0.15 m
Therefore the force, F of the spring = 300 N/m×0.15 m = 45 N
Mass of box = 0.2 kg
Work, W, done by the spring = and the kinetic energy gained by the box is given by KE =
Since work done by the spring = kinetic energy gained by the box we have
=
therefore we have v =
=
=
= 5.81 m/s
Therefore the maximum height is given by
v² = 2·g·h or h = =
= 1.72 m