Answer: D
8.403 m/s
Explanation:
Given that the women's world record for the 400-meter run around an oval track is held by Marita Koch, with a time of 47.60
seconds.
Her average velocity during this race will be
Velocity = distance/ time
Velocity = 400 / 47.6
Velocity = 8.403 m/s
Therefore, her average velocity during this race will be 8.403 m/s
D is therefore the correct answer.
Power = Work/time
Work = Force*Displacement
Power = (Force*Displacement )/time
500 W= F*5m/10s
F = 500W*10s/5m =1000 J/s*s/m = 1000 J/m= 1000 N
Answer:
horizontal velocity vh = 6*cos(30°) = 6*(√3)/2 = 3√3 m/s
initial vertical velocity vv = 6*sin(30°) = 6/2 = 3m/s
Using s = ut + at2/2 for change in vertical distance in time t, with acceleration a (-9.8m/s2) and initial velocity u (vv = 3m/s) we have
0 = 3*t - 9.8*t2/2 or t = 6/9.8 s (ignoring the t = 0 solution, which just represents staying still!).
The horizontal distance in time t is vh*t or 3√3*6/9.8 m
Explanation:
New force is 1/4 of force when distance is doubled