You cannot average the two speeds in conditions of equal distance. You need equal time..
Look at it this way: 15 m/s for 10 km would take 666.67 seconds.
25 m/s for another 10 km would take 400 seconds. Total time: 1066.67 seconds. Total distance 20 km. This average speed 20000 m/1066.67 seconds = 18.75 m/s.
If you had gone 15 m/s for the same *time* as going at 25 m/s, then you could have averaged the speeds directly.
To get a real feel for this, imagine going at 1 m/s for 10 km, and then going at the speed of flight for the other 10 km. The first part would take 10000 seconds (nearly 3 hours) and the second almost zero time. Would your average speed be half the speed of light?
Force = Mass . Accelaration
f=ma
force is directly proportional to mass and accelaration
therefore when mass of the object is doubled, the accelaration would be halved
since
a=f/m
The answer would be C. The gravitational force between two bodies however it is too small that it is overshadowed by that of earth. Gravitational force is the weakest force of all. Each body with a mass exerts a gravitational force onto each other but this value is so small that it can be neglected.
The speed of the vehicle after the push is 2.7 m/s.
<h3>What is velocity?</h3>
velocity is the rate of change of displacement.
To calculate the velocity of the vehicle, we use the formula below.
Formula:
- v = √[2(W-W')/m]............... Equation 1
Where:
- W = work done by the pusher
- W' = Work done by friction
- m = mass of the car
From the question,
Given:
- W = 6500 J
- W' = 2000 J
- m = 1200 kg
Substitute these values into equation 1
- v = √[2(6500-2000)/1200]
- v = √(7.5)
- v = 2.7 m/s
Hence, the speed of the vehicle after the push is 2.7 m/s.
Learn more about velocity here:
#SPJ1
Well one of the factors is that the species is poorly adapted to the their environment and die off