Answer:
Speed = 2.25 m/s
Explanation:
(Assume a running step is 1.5 m long)
Given the following data;
Energy = 0.6J
Power = 61 Watts
Mass = 68 kg
To find how fast the person running;
First of all, we would determine the total mechanical energy being dissipated by the person.
Total energy = 0.6 * 68
Total energy = 40.8 Joules
Next, we find the time;
Energy = power * time
40.8 = 61 * time
Time = 61/40.8
Time = 1.5 seconds
Finally, to find the speed;
Speed = distance/time
Speed = number of steps * time
Speed = 1.5 * 1.5
Speed = 2.25 m/s
Answer:
You never know if the medication could make you worse
Explanation:
Lightning does not come from the ground. It comes from the sky, mostly during thunderstorms. Watch the sky the next time you see a thunderstorm. You might see the lightning strike.
Answer:
k = 0.7
Explanation:
mass (m) = 55 kg
slope of hill (θ) = 35 degrees
coefficient of friction (k) = 0.12
time (t) = 5 s
acceleration due to gravity (g) = 9.8 m/s^{2}
What is the new coefficient of friction if the friction of the snow suddenly increased and made the net force on the skier zero?
we can find the coefficient of friction by applying newtons second law of motion, force = mass x acceleration
where
- force = force of the skier - friction force
- force of the skier = mg.Sinθ
- friction force = k.mg.Cosθ
- therefore force = mg.Sinθ - k.mg.Cosθ
therefore force = mass x acceleration now becomes
mg.Sinθ - k.mg.Cosθ = mass x acceleration
mg.Sinθ - k.mg.Cosθ = ma
mg (Sinθ - k.Cosθ) = ma
g(Sinθ - k.Cosθ) = a
for the net force on the skier to be zero, the acceleration of the skier has to be zero.
therefore g(Sinθ - k.Cosθ) = 0
now substituting the required values into the equation above we have
9.8 ( sin 35 - k.cos 35 ) = 0
9.8 (0.5736 - k.0.8192) = 0
5.6213 - 8.028k = 0
5.6213 = 8.028k
k = 0.7
