I think the answer is 2283g
Answer:
v = 7.65 m/s
t = 0.5882 s
Explanation:
We are told that the salmon started downstream, 3.18 m away from a waterfall.
Thus, range = 3.18 m
Since the horizontal velocity component is constant, then;
Range = vcosθ × t
Thus,
vcosθ × t = 3.18 - - - (eq 1)
We are told the salmon reached a height of 0.294 m
Thus, using distance equation;
s = v_y•t + ½gt²
g will be negative since motion is against gravity.
s = v_y•t - ½gt²
Thus;
0.294 = v_y•t - ½gt²
v_y = vsinθ
Thus;
0.294 = vtsinθ - ½gt² - - - (eq 2)
From eq(1), making v the subject, we have;
v = 3.18/tcosθ
Plugging into eq 2,we have;
0.294 = (3.18/tcosθ)tsinθ - ½gt²
0.295 = 3.18tanθ - ½gt²
We are given g = 9.81 m/s² and θ = 45°
0.295 = (3.18 × tan 45) - ½(9.81) × t²
0.295 = 3.18 - 4.905t²
3.18 - 0.295 = 4.905t²
4.905t² = 2.885
t = √2.885/4.905
t = 0.5882 s
Thus;
v = 3.18/(0.5882 × cos45)
v = 7.65 m/s
No one can really tell exactly how old the universe is. However, scientists have attempted to estimate the time by using the concept of Doppler effect which depends on the frequency of the stars and their relative velocities. From literature, the universe is about 13.82 billion years old. Thus, the age of the universe is 13.82×10⁹ times longer than a year.
b). The power depends on the RATE at which work is done.
Power = (Work or Energy) / (time)
So to calculate it, you have to know how much work is done AND how much time that takes.
In part (a), you calculated the amount of work it takes to lift the car from the ground to Point-A. But the question doesn't tell us anywhere how much time that takes. So there's NO WAY to calculate the power needed to do it.
The more power is used, the faster the car is lifted. The less power is used, the slower the car creeps up the first hill. If the people in the car have a lot of time to sit and wait, the car can be dragged from the ground up to Point-A with a very very very small power ... you could do it with a hamster on a treadmill. That would just take a long time, but it could be done if the power is small enough.
Without knowing the time, we can't calculate the power.
...
d). Kinetic energy = (1/2) · (mass) · (speed squared)
On the way up, the car stops when it reaches point-A.
On the way down, the car leaves point-A from "rest".
WHILE it's at point-A, it has <u><em>no speed</em></u>. So it has no (<em>zero</em>) kinetic energy.