Answer:
2.5 m/s
Explanation:
The speed of the animal is given by the ratio between the distance travelled by the animal and the time elapsed:

where d is the distance travelled and t the time elapsed. Note that this quantity is also equal to the slope of the curve.
In the time interval 0-20 s, we have
d = 50 m - 0 m = 50 m
t = 20 s - 0 s = 20 s
So, the speed is

The car at 60 kph has 9 times more kinetic energy than the car traveling at 20 kph. This assumes that both cars have the same mass. Kinetic energy depends on the square of thee speed so if one car is going 3 times faster, its kinetic energy will be 3^2 ( = 9 ) greater. The car going at 60 kph will have 4 times the KE of the car going at 30 kph ( again assuming that the cars have the same mass.)
<span>In this problem, we need to solve for Bubba’s mass. To do this, we let A be the area of the raft and set the weight of the displaced fluid with the raft alone as ρwAd1g and ρwAd2g with the person on the raft, </span>where ρw is the density of water, d1 = 7cm, and d2= 8.4 cm. Set the weight of displaced fluid equal to the weight of the floating objects to eliminate A and ρw then solve for m.
<span>ρwAd1g = Mg</span>
ρw<span>Ad2g = (M + m) g</span>
<span>d2∕d1 = (M + m)/g</span>
m = [(d2<span>∕d1)-1] M = [(8.4 cm/7.0 cm) - 1] (600 kg) =120 kg</span>
This means that Bubba’s mass is 120 kg.
The answer is Air Resistance
Answer:
5.791244495 KNm
Explanation:
The height h is given by,
Potential energy, PE is given by
PE=mgh where m is mass of the woman, g is acceleration due to gravity whose value is taken as
and h is already given hence substituting 77 Kg for m we obtain
PE=21.6567095 KNm
We also know that Kinetic energy is given by
where v is the velocity and substituting v for 20.3 we obtain
KE=15.865465 KNm
Friction work is the difference between PE and KE hence
Friction work=21.6567095 KNm-15865.465 Nm=5.791244495 KNm