Answer:
The average speed would be 279.167 meters per second.
Explanation:
Speed is the magnitude that expresses the variation in position of an object and as a function of time. In other words, speed is defined as the relationship established between the distance traveled and the time elapsed in the movement of a mobile.
Speed can be calculated using the following expression:

In this case:
- distance= 7,035 km
- time= 7 hours
Since the required unit of speed is meter per second, then you convert from km to meters for the case of distance, and from hours to seconds for the case of time. So:
- distance= 7,035 km= 7,035,000 m (being 1 km= 1,000 m)
- time= 7 hours= 420 minutes= 25,200 seconds (being 1 hour=60 minutes and 1 minute=60 seconds)
Replacing in the definition of speed:

Solving:

Then, <u><em>the average speed would be 279.167 meters per second.</em></u>
Is there any answers choices..?
Answer:
The answer is C she didn't mark C so its your best best of trying.Good Luck!
The time taken for the athlete to finish the race is 20 s (Option A)
<h3>What is power? </h3>
Power is simply defined as the rate at which work is done. It can be expressed mathematically as
Power (P) = work (W) / time (t)
But
Work = weight × distance
Therefore,
Power = (weight × distance ) / time
<h3>How to determine the time </h3>
- Mass (m) = 55 Kg
- Acceleration due to gravity (g) = 9.8 m/s²
- Weight = mg = 55 × 9.8 = 539 N
- Power (P) = 5.4 KW = 5.4 × 1000 = 5400 W
- Distance (d) = 200 m
- Time (t) =?
Power = (weight × distance ) / time
5400 = (539 × 200) / t
5400 = 107800 / t
Cross multiply
5400 × t = 107800
Divide both side by 5400
t = 107800 / 5400
t = 20 s
Learn more about power:
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Answer:
1 kg
Explanation:
The container has negligible mass and no heat is loss to the surrounding.
Mass of ice = 0.4kg, initial temperature of ice = -29oC, final temperature of the mixture = 26oC, mass of water (m2) = ?kg, initial temperature of water = 80oC, c ( specific heat capacity of water ) = 4200J/kg.K, Lf = heat of fusion of water = 3.36 × 10^5 J/kg
Using the formula:
Quantity of heat gain by ice = Quantity of heat loss by water
Quantity of heat gain by ice = mass of ice × heat of fusion of ice + mass of water × specific heat capacity of water = (0.4 × 3.36 × 10^ 5) + (0.4 × 4200 × (26- (-29) = 13.44 × 10^4 + 9.24 × 10^ 4 = 22.68 × 10^4 J
Quantity of heat loss by water = m2cΔT
Quantity of heat loss by water = m2 ×4200× (80 - 26) = m(226800)
since heat gain = heat loss
22.68 × 10^4 = 226800 m2
divide both side by 226800
226800 / 226800 = m2
m2 = 1 kg