When a swimmer pushes through water to swim they are propelled forward because of the water resistance against the hand and feet. It's A. The water doesn't automatically push the swimmer forward. It releases a reaction after the swimmer pushes through the water.
Answer:
26.5 minutes
Explanation:
When the airplane is flying due West from Denver to Reno, the due-East wind with speed of 80km/h would reduce the ground speed by 80 km/h.
Its Denver to Reno ground speed is 900 - 80 = 720 km/h
The time it takes to cover 1200km at this speed is 1200 / 720 = 1.67 hours
On the other hand, when it returns from Reno to Denver in the due-East direction, the due-East wind with speed of 80km/h would add to the ground speed by 80 km/h
Its Reno to Denver ground speed is 900 + 80 = 980 km/h
The time it takes to cover 1200 km at this speed is 1200 / 980 = 1.22 hours
The difference it flight time would be 1.67 - 1.22 = 0.44 hours or 26.5 minutes
Answer:
a)3312 x 10⁴ J
b)I = 57.5 A
c)9200 W
Explanation:
Given that
P =4600 W
Time t= 2 h = 2 x 3600 s= 7200 s
We know that
1 W = 1 J/s
a)
Energy stored in the battery = P .t
=4600 x 7200 J
=3312 x 10⁴ J
b)
We know that power P given as
P = V .I
V=Voltage ,I =Current
4600 = 80 x I
I = 57.5 A
c)
The energy supplied = 4600 x 2 = 9200 W
Answer:
The sum of the lengths of the sides is 2292 yards and the sum of the lengths of the triangle is 3056 yards
Explanation:
Since y represents the length of fence that is opposite (parallel) to the river and x represent the length of fence perpendicular to the river.
Therefore since we can use 3,056 yards of fencing
Side perpendicular to the river = x and,
Side opposite to the river = y = 3056 - 2x
The area of the rectangle formed (A) = Perpendicular side × Parallel side
∴ A = x(3056 - 2x) = 3056x - 2x²
A = 3056x - 2x²
To maximize the area, A' (dA/dx) = 0
∴ A' = 3056 - 4x = 0
3056 - 4x = 0
4x = 3056
x = 764 yards
y = 3056 - 2x = 3056 - 2(764) = 1528 yards.
Side perpendicular to the river = 764 yards and,
Side opposite to the river = 1528 yards
The sum of the lengths of the sides = 764 + 1528 = 2292 yard and the sum of the lengths of the triangle = 764 + 764 + 1528 = 3056 yards
