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Because if an object is moving at a constant speed the force of friction must equal the applied (horizontal) force, and for it to be accelerating or decelerating, the force of friction and the applied force must be unequal
Answer:
Explanation:
Here the total force at the horizontal components will be equal to the centripetal force on the car. So we will have:
(1)
- f(fr) is the friction force
- N is the normal force
Now, the sum of forces at the vertical direction is equal to 0.
(2)
Let's combine (1) and (2) to find f(fr)

I hope it helps you!
Answer:
1.2 Hz
Explanation:
Frequency: This can be defined as the number of cycles completed in one seconds. The unit of frequency is Hertz (Hz)
From the question above,
f = N/t.................... Equation 1
Where f = frequency, N = number of wave or cycle completed by Johnny, t = time take to complete the waves.
Given: N = 12 waves, t = 10 s
Substitute into equation 1
f = 12/10
f = 1.2 Hz
<h2>your answer is going to be image 1 that one looks the most decent </h2>
Answer:
t=0.417s
Explanation:
After the ball hits the racket it is in freefall(assume air resistance as negligible)
so a=-g
use
x-x0=v0t+1/2at^2
Plug in givens
20=50t-4.9t^2
Solve quadratic equation using quadratic formula
t= 0.417 seconds, (the other answer is extraneous because it is too big because in 1 second, the ball travels 50 meters)