Answer:
Speed of the runner during video interval is 6.49 m/s
Explanation:
According to the problem,
Number of frames recorded by camera in 1 second = 50
Time takes by camera to record 1 frame = (1/50) s
Time taken by camera to record 77 frames, t =
s
Distance covered by the runner during the video recording, d = 10 m
Speed, v = 
Substitute the values of d and t in the above equation.
v = 
v = 6.49 m/s
Answer:
B and D
Explanation:
Fresh water is essential to all life on Earth. Most of Earth's water is stored in the oceans.
We have that the momentum p is given by the formula p=mv where m is the mass and v is the velocity. Since for A p=-14kgm/s and m=7, we have that the velocity is -14/7=-2m/s. Hence its speed is 2 m/s.
For b we have that p=15kgm/s and v=3m/s. Because m=p/v, we have m=3kg.
We also have that the momentum is conserved in this system. Hence, the net sum of the momentum of the 2 snowballs equals the momentum of the single giant ball. Hence, p(total)=p(combined)=-14+15=1kgm/s (momentum is a vector; the positive sign means that it tends to the positive direction).