Answer is on the image with the explanation. I hope that might help you with the answers
Answer:
The skater has mechanical/gravitational potential energy at the two meter mark. The skater gets to two meters high on the other end of the ramp. In terms of the conservation of energy, the skater will never go higher than two meter on the other end of the the ramp because energy can be neither created nor destroyed.
Explanation:
I hoping it is right!!!∪∧∪ ∪ω∪
According to Newton`s law. Force exerted by car,

After adding an additional 400 kg of mass, the force will be same therefore the acceleration

Thus, the acceleration after adding the masses is 1.47 \ m/s^2.
Each person is 80kg. 320/4
Answer:
The answer to your question is : 521.8 m
Explanation:
Data:
Different heights
Time first object (tfo) = 10.7 s
Time second object (tso)= 14.8 s
Initial speed of both objects(vo) = 0 m/s
a = 9.81 m/s²
Formula:
h = vot + 1/2 (a)(t)² but vo = 0 so, h = 1/2 (a)(t)²
Then, height fo h = 1/2 (9.81)(10.7)² = 561.6 m
height so h = 1/2(9,81)(14.8)² = 1074.4 m
Difference in their heights = 1074.4 m - 561.6 m = 521.8 m