Answer: 0.204 s
Explanation:
The speed of sound
is defined as the distance traveled
in a especific time
:
Where:
is the speed of sound in seawater
is the time the sound wave travels from the dolphin and then returns after the reflection
is twice the distance between the dolphin and the object to which the sound waves are reflected
Finding
:
<u>Finally:</u>
You want v2 = v1 + at
v is measured in m/s, a in m/s2, and t in s.
the dimensions multiply like algebraic quantities.
so because v2 is measured in m/s, then (v1 + at) has to come out in m/s
the units for (v1 + at) are (m/s) + (m/s2)(s)
time "s" cancels out one acceleration "s", so it comes ut to (m/s) + (m/s), which = (m/s).
if you had (v1t + a), then you would have (m/s)(s) + (m/s2) which = (m) + (m/s2), which doesn't work.
There are some missing data in the text of the problem. I've found them online:
a) coefficient of friction dry steel piston - steel cilinder: 0.3
b) coefficient of friction with oil in between the surfaces: 0.03
Solution:
a) The force F applied by the person (300 N) must be at least equal to the frictional force, given by:

where

is the coefficient of friction, while N is the normal force. So we have:

since we know that F=300 N and

, we can find N, the magnitude of the normal force:

b) The problem is identical to that of the first part; however, this time the coefficienct of friction is

due to the presence of the oil. Therefore, we have:
Answer:
a = 10.07m/s^2
Their acceleration in meters per second squared is 10.07m/s^2
Explanation:
Acceleration is the change in velocity per unit time
a = ∆v/t
Given;
∆v = 50.0miles/hour - 0
∆v = 50.0miles/hours × 1609.344 metres/mile × 1/3600 seconds/hour
∆v = 22.352m/s
t = 2.22 s
So,
Acceleration a = ∆v/t = 22.352m/s ÷ 2.22s
a = 10.07m/s^2
Their acceleration in meters per second squared is 10.07m/s^2