Explanation:
If box weight 25N on ground
MA=F
M(10)=25
M=2.5Kg
<span>So we want to know what statement is an accurate description of vibrations. So humans can hear sound frequencies from 20-20000 Hz. Below 20 Hz is infra sound and above 20000 Hz is ultra sound. Humans cant hear both infra sound and ultra sound so the correct answer is A.</span>
Answer:
Distance =60m, Time = 6s, Speed = ?
Speed = distance/time
= 60/6
=10m/s
Explanation:
Hope that this is helpful.
Have a nice day.
Answer: Remember speed is distance divided by time, so if he travels 1000 m in 7.045 s, his speed is
(1000 m)/(7.045 s) = 141.9 m/s.
Note there are 1609 metres in a mile, or 1 mi = 1609 m, so m = 1/1609 mi, or
141.9/1609 mi/s = 0.08822 mi/s. Now, note that 1 h = 3600 s, so the speed is
0.08822*3600 mi/h = 317.6 mi/h.
Halflife is the time taken by a radioactive substance by half its original mass. In this case the half life of the substance is 3 hours.
Therefore; New mass = Original mass × (1/2)^n where n is the number of half lives. In this case, the half life is 3 hours and therefore; the number of half lives in 6 hours will be two.
= if the original mass is 100%
new mass = 100 × (1/2)^2
= 100 × 1/4 = 25%
The remaining mass will be 1/4 of the original mass, meaning a fraction of 3/4 of the initial mass will have decayed.
Thus; the answer is 3/4
