Answer:
4) True. The change of direction needs an unbalanced force
Explanation:
Let us propose the resolution of the problem using Newton's second law.
F = m a
As the car is spinning the acceleration is centripetal
a = v2.r
F = m v2 / r
We can see that as the velocity of a vector even if its module does not change, the change of direction requires an external force.
Now we can analyze the statement if they are true or false
1) and 3) False, even when the speed changes, the direction changes
2) False with the speed change can be determined
4) True. The change of direction needs an unbalanced force
5) False are different things. the direction is where it is going and the speed is the magnitude of the vector
Absolutely false!! Creativity, curiosity encouraged in Scientific endeavors. Science is all about exploring knowledge, it just promotes intelligency!
In Short, Your Answer would be "False"
Hope this helps!
Answer:
5 hours
Explanation:
Let the required time be x hours. The time will be the same for both cars.
The cars will cover different distances because they are travelling at different speeds.
<em>D=S×T
</em>
The distance travelled by the slower car = 50×x miles.
The distance travelled by the faster car = 58×x miles.
The two distances differ by 40 miles.
58x−50x=40
8x=40
x=5 hours
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
A second method:
The difference in the distances is 40 miles
The difference in the speeds is #8mph.
The time to make up the 40 miles=
=5 hours
Answer:
5.0 m/s
Explanation:
The horizontal motion of the salmon is uniform, so the horizontal component of the salmon's velocity is constant and it is

where u is the initial speed and
. The horizontal distance travelled by the salmon is

where d = 1.95 m and t is the time needed to reach the final point.
Re-arranging for t,
(1)
Along the vertical direction, the equation of motion is

where:
y = 0.311 m is the final height reached by the salmon
h = 0 is the initial height
is the vertical component of the initial velocity of the salmon
is the acceleration of gravity
t is the time
Substituting t as found in eq.(1), we get the equation

and we can solve this formula for u, the initial speed of the salmon:

Answer:
The frequency of the phonograph record is 0.2 Hz
Explanation:
The frequency of an object moving in uniform circular motion is the number of completed cycles the object makes in a specified time period
The given parameters of the phonograph record are;
The radius of the record = 0.15 m
The number of times the phonograph record rotates, n = 18 times
The time it takes the phonograph record to rotate the 18 times, t = 90 seconds
The frequency of the phonograph record, f = (The number of times the phonograph record rotates) ÷ (The time it takes the phonograph record to rotate the 18 times)
∴ The frequency of the phonograph record, f = n/t = 18/(90 s) = 0.2 Hz
The frequency of the phonograph record = 0.2 Hz.