Momentum = (mass) x (speed)
Divide each side by (speed): Mass = (momentum) / speed
Mass = (45,000 kg-m/s) / (30 m/s) =
1,500 kg .
Complete question is: While running, a person dissipates about 0.60 J of mechanical energy per step per kilogram of body mass. If a 60-kg person develops a power of 70 W during a race, how fast is the person running? (Assume a running step is 1.5 m long).
Answer: The person running at a speed of 2.91 m/s.
Explanation:
Given: Mass of runner = 60 kg
Runner dissipates = 0.6 J/kg per step
Average power = 70 W
1 step = 1.50 m
Energy dissipated by the runner is as follows.
Formula used to calculate the value of one step 'S' is as follows.
It is known that average velocity is equal to the total distance divided by time interval.
So, total distance for the given situation is as follows.
Hence, speed of the person is calculated as follows.
Thus, we can conclude that the person running at a speed of 2.91 m/s.
Answer:
the spear will end up above the fish relative to the actual position of the fish.
Explanation:
due to refraction of light coming from the fish the fish will appear slightly above from its real position
So due to this refraction the spearfisher will throw the spear directly at the image of the fish due to which it will not reach the position of fish but it will reach the position above the fish.
So here we can say that the spear will end up above the fish relative to the actual position of the fish
The rider's horizontal motion, and how much ground he covers before he hits it, have nothing to do with how long he takes to hit the ground. The problem is simply: "How long does it take an object to fall 1.12 m from rest ?"
This seems like a good time to use this formula:
Distance fallen from rest = (1/2) (acceleration) (time)²
The problem doesn't tell us what planet the skateboarder is exercising on. I'm going to assume it's on Earth, where the acceleration of gravity is 9.8 m/s². And now, here's the solution to the problem I just invented:
1.12 m = (1/2) (9.8 m/s²) (time)²
Time² = (1.12 m) / (9.8 m/s²)
Time² = 0.1143 sec²
Time = √(0.1143 sec² )
<em>Time = 0.34 second</em>
Ionic bonds with electrostatic attractions