Speed = (acceleration) x (time)
Velocity = (speed) in (direction of the speed)
Speed = (-3 m/s²) x (5 s) = 15 m/s
Velocity =
(15 m/s) in the direction opposite to the direction you call positive.
Displacement = (distance between start-point and end-point)
in the direction from start-point to end-point.
Distance = (1/2) (acceleration) (time)²
Distance = (1/2) (3 m/s²) (5 s)²
= (1/2) (3 m/s²) (25 s²) = 37.5 meters
Displacement =
37.5 meters in the direction opposite to the direction you call positive.
Anything less dense than water will float, like oil. Anything more dense than water will sink, like rock.
The answer is C. I hope I helped!
Weight equals mass times gravitational acceleration=400N, so mass=400/9.8=41kg approx.