Answer: 1479watts
Explanation:
Power is defined as the energy expended or work done in a specific time.
Mathematically,
Power = Workdone/time taken
Since work done is force × distance
Power = force × distance/time
Force = Mary's weight = 87N
Distance = height of the flight = 102meters
Time = 6.0seconds
Substituting in the formula we have;
Power = 87 × 102/6
Power = 1,479watts
Note that the time must be in seconds before usage. If its given in minutes, you will have to convert to seconds
Answer:
a) 17.49 seconds
b) 13.12 seconds
c) 2.99 m/s²
Explanation:
a) Acceleration = a = 1.35 m/s²
Final velocity = v = 85 km/h = 
Initial velocity = u = 0
Equation of motion
Time taken to accelerate to top speed is 17.49 seconds.
b) Acceleration = a = -1.8 m/s²
Initial velocity = u = 23.61\ m/s
Final velocity = v = 0
Time taken to stop the train from top speed is 13.12 seconds
c) Initial velocity = u = 23.61 m/s
Time taken = t = 7.9 s
Final velocity = v = 0
Emergency acceleration is 2.99 m/s² (magnitude)
Answer:
The coefficient of rolling friction will be "0.011".
Explanation:
The given values are:
Initial speed,
then,
Distance,
s = 18.2 m
The acceleration of a bicycle will be:
⇒ 
On substituting the given values, we get
⇒ 
⇒ 
⇒ 
⇒ 
As we know,
⇒ 
and,
⇒ 
⇒ 
On substituting the values, we get
⇒ 
⇒ 
Answer: The volume of gas expands because of the decrease in pressure as he tries to exit the water body, therefore he must take necessary precaution.
Explanation:
Using Boyle's law which states that the the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature
ie P1VI=P2V2
A diver absorbs compressed nitrogen gas when he dives into the water body, As he ascends out of the water body having less pressure, the volume of nitrogen gas which he absorbs will tend to expand following Boyle's Law. Therefore a scuba driver should not rises quickly but slowly to the surface or else the expanding nitrogen gas can cause tiny bubbles in his blood and tissue to form together with joints pains and eventually cause decompression sickness needing medical attention.
Answer:
72 km/hr. ...jshdhdhddjidididdiididudd
