Answer:
Explanation:
Well, lets say you park your car on the top of a hill, gravitational energy prevents it from the car falling back. Or a snow pack, aka before a potential avalanche. Though gravity cannot keep it safe forever, gravitational energy keeps it from crashing asap. In this case, it gives you time to escape. Altogether, gravitational force keeps the earth in it's atmosphere.
<u>Correct Question:</u>
Calculate the distance (in km) charlie runs if he maintains an average speed of 8 km/hr for 1 hour
<u>Answer:</u>
The total distance covered by Charlie is 8 km in 1 hour.
<u>Explanation:</u>
The average velocity as given in the question is,
v = 8 km/hr
Total time taken,
As we know the formula to evaluate the total distance d when the average velocity and time is given;
Hence, the total distance covered by Charlie in 1 hour will be 8 km.
Answer:
a) W = 46.8 J and b) v = 3.84 m/s
Explanation:
The energy work theorem states that the work done on the system is equal to the variation of the kinetic energy
W = ΔK = -K₀
a) work is the scalar product of force by distance
W = F . d
Bold indicates vectors. In this case the dog applies a force in the direction of the displacement, so the angle between the force and the displacement is zero, therefore, the scalar product is reduced to the ordinary product.
W = F d cos θ
W = 39.0 1.20 cos 0
W = 46.8 J
b) zero initial kinetic language because the package is stopped
W - = -K₀
W - fr d= ½ m v² - 0
W - μ N d = ½ m v
on the horizontal surface using Newton's second law
N-W = 0
N = W = mg
W - μ mg d = ½ m v
v² = (W -μ mg d) 2/m
v = √(W -μ mg d) 2/m
v = √[(46.8 - 0.30 4.30 9.8 1.20) 2/4.3
]
v = √(31.63 2/4.3)
v = 3.84 m/s
A. Is very attractive. If it's sublimation directly from water vapor in the air to ice on the glass, then yes. But from liquid water mist to water ice, no. Ice is less dense than water. That's why cubes float in your soda. Better leave 'A' alone. . . . D. Ice pellets turn to liquid. That one's good.