Work is equal to the force applied times the displacement. Since you pull the wagon at constant speed this means that there is no acceleration on the wagon as it does not change speed. F=ma. Since a=0, F=0. Therefore no work has been done in this situation
Answer:
Explanation:
d = Distance traveled = 40.8 km
s = Speed of jet = 340 m/s
Time is given by
The time taken to complete the journey is .
<span>A particular frost-free refrigerator uses about 710kWh of electrical energy per year. You are to express this amount of energy in J, kJ, & Calories.
1 year (365 days / 1 year)(24 hours / 1 day)(3600s / 1h) = 31,536,000s
710 kWh/yr (1 yr) = 710 kWh
710 x 10^3 Wh = </span>710 x 10^3(J/s)(31,536,000s)<span> = 2.24 x 10^13 J
</span>2.24 x 10^13 J = 2.24 x 10^10 kJ = 5.35 x 10^12 cal
Answer:
h' = 603.08 m
Explanation:
First, we will calculate the initial velocity of the pellet on the surface of Earth by using third equation of motion:
2gh = Vf² - Vi²
where,
g = acceleration due to gravity on the surface of earth = - 9.8 m/s² (negative sign due to upward motion)
h = height of pellet = 100 m
Vf = final velocity of pellet = 0 m/s (since, pellet will momentarily stop at highest point)
Vi = Initial Velocity of Pellet = ?
Therefore,
(2)(-9.8 m/s²)(100 m) = (0 m/s)² - Vi²
Vi = √(1960 m²/s²)
Vi = 44.27 m/s
Now, we use this equation at the surface of moon with same initial velocity:
2g'h' = Vf² - Vi²
where,
g' = acceleration due to gravity on the surface of moon = 1.625 m/s²
h' = maximum height gained by pellet on moon = ?
Therefore,
2(1.625 m/s²)h' = (44.27 m/s)² - (0 m/s)²
h' = (1960 m²/s²)/(3.25 m/s²)
<u>h' = 603.08 m</u>
When hockey players push the puck along the ice it slides causing heat which melts the ice causing the friction against the ice to be less.
