Answer:
a) v = 141.9 m/s
b) v = 317.4 miles/h
Explanation:
a) How fast was he moving in meters per second?

Hence, the jet ski is moving at 141.9 meters per second.
b) How fast was he moving in miles per hour?
Therefore, the jet ski is moving at 317.4 miles per hour.
I hope it helps you!
Same temperature and difference in air pressure
Answer:
Speed of the helium after collision = 246 m/s
Explanation:
Given that
Mass of helium ,m₁ = 4 u
u₁=598 m/s
Mass of oxygen ,m₂ = 32 u
u₂ = 401 m/s
v₂ =445 m/s
Given that initially both are moving in the same direction and lets take they are moving in the right direction.
Speed of the helium after collision = v₁
There is no any external force on the masses that is why the linear momentum will be conserve.
Initial linear momentum = Final linear momentum
P = m v
m₁u₁+m₂u₂ = m₁v₁+m₂v₂
598 x 4 + 32 x 401 = 4 x v₁+ 32 x 445
v₁ = 246 m/s
Speed of the helium after collision = 246 m/s
Get to school and learn boi