Answer:
5.3 m/s
Explanation:
First, find the time it takes for him to fall 7m.
y = y₀ + v₀ t + ½ at²
0 = 7 + (0) t + ½ (-9.8) t²
0 = 7 − 4.9 t²
t ≈ 1.20 s
Now find the velocity he needs to travel 6.3m in that time.
x = x₀ + v₀ t + ½ at²
6.3 = 0 + v₀ (1.20) + ½ (0) (1.20)²
v₀ ≈ 5.27 m/s
Rounded to two significant figures, the man must run with a speed of 5.3 m/s.
Answer:
It will take 15.55s for the police car to pass the SUV
Explanation:
We first have to establish that both the police car and the SUV will travel the same distance in the same amount of time. The police car is moving at constant velocity and the SUV is experiencing a deceleration. Thus we will use two distance fromulas (for constant and accelerated motions) with the same variable for t and x:
1. 
2. 
Since both cars will travel the same distance x, we can equal both formulas and solve for t:
We simplify the fraction present and rearrange for our formula so that it equals 0:
In the very last step we factored a common factor t. There is two possible solutions to the equation at 
and:
What this means is that during the displacement of the police car and SUV, there will be two moments in time where they will be next to each other; at 
(when the SUV passed the police car) and 
(when the police car catches up to the SUV)
The point at which all motion stops.
Answer:
Increases, increases
Explanation:
The current is directly proportional to the voltage and inversely proportional to the resistance. The implication of this is that, whenever the voltage is increased, the current increases simultaneously. On the other hand, if the resistance is increased, the current will decrease accordingly and vice versa.
Recall that power is given by P= V^2/R where;
P= power, V= voltage and R= resistance
We can see that power and resistance are inversely related hence decreasing the resistance increases the power output of the lightbulb.
Answer: The energy carried by an electromagnetic wave is proportional to the frequency of the wave.
Explanation:
Electromagnetic waves that are of higher energy than visible light (higher frequency, shorter wavelength) include ultraviolet light, X-rays, and gamma rays.
