A. Acceleration is the answer to you question. When an object changes velocity it can accelerate.<span />
Answer:
28.6260196842 m
Explanation:
Let h be the height of the building
t = Time taken by the watermelon to fall to the ground
Time taken to hear the sound is 2.5 seconds
Time taken by the sound to travel the height of the cliff = 2.5-t
Speed of sound in air = 340 m/s
For the watermelon falling

For the sound
Distance = Speed × Time

Here, distance traveled by the stone and sound is equal


The time taken to fall down is 2.4158 seconds

Height of the buidling is 28.6260196842 m
Answer:
Correct option : (c) period.
Explanation:
The time that is required for a vibrating object to complete one full cycle is called the time period. If f is the frequency of a wave, then the relation between the frequency and the time period is given by :

These are the characteristics of a wave. Some other characteristics are wavelength, amplitude, intensity etc. So, the correct option is (c) "period".
Answer:
yes
Explanation:
cuz 15x2=30 30x2=60 60=1 hour, and the limited is 80 km per hour
15=25
15x4=60 25x4=100
so yes
he was going 100km per hour