Answer:
No
Explanation:
Unless there are other external forces, this will never be true. Because according to energy conservation, potential energy will be converted to kinetic energy as the ball falls down (so it loses height and gain speed). And vice versa, kinetic to potential when it bounces back. So the potential energy after must be the same (or smaller if losing heat to external environment), so it can only get the the same height or less, but not more.
Answer:
(a) 3.13 m/s
(b) 9.9 m/s
(c) 7.73 m/s
Explanation:
u = 0 m/s, g = 9.8 m/s^2
Let v be the velocity of ball as it hit the ground.
(a) h = 0.5 m
Use third equation of motion.
v^2 = u^2 + 2 g h
v^2 = 0 + 2 x 9.8 x 0.5
v^2 = 9.8
v = 3.13 m/s
(b) h = 5 m
Use third equation of motion.
v^2 = u^2 + 2 g h
v^2 = 0 + 2 x 9.8 x 5
v^2 = 98
v = 9.9 m/s
(c) h = 10 feet = 3.048 m
Use third equation of motion.
v^2 = u^2 + 2 g h
v^2 = 0 + 2 x 9.8 x 3.048
v^2 = 59.74
v = 7.73 m/s
This is the Doppler effect.
1. As the sound leaves the horn the sound waves are at first close to each other and as they move outwards they become further apart. The closer the sound waves are the louder the noise.
As the car gets the closer the sound waves get closer, so the horn becomes louder.
2. As the horn moves away, the sound waves become less frequent, causing the pitch to get lower.
Answer:
No
Explanation:
The fastest recorded time for a person to run 100 metres is 9.58 seconds, which is the equivalent of 10.4 metres per second
