Answer:
Part a)
a = - 8.45 m/s/s
Part b)

Part c)

Explanation:
Part a)
when car apply brakes then the friction force on the car in front of us is given as

here we need to find deceleration due to friction



Part b)
Braking distance of the car is the distance that it move till it stops
so we will have



Part c)
Since we know that average reaction time for human is 0.424 s
now we know that during reaction time our car will travel at uniform speed
so we will have



Answer:
(E)56.0 m/s
Explanation:
Height =h=-160 m
Because the wallet moving in downward direction
Time=t=7 s
Final speed of wallet=v=0
We have to find the speed of helicopter ascending at the moment when the passenger let go of the wallet.

Where 
Substitute the values



Option (E) is true
Answer:
The magnitude of the acceleration of the tip of the minute hand of the clock
.
Explanation:
Given that,
Length of minute hand = 0.55 m
Length of hour hand = 0.26 m
The time taken by the minute hand to complete one revelation is

We need to calculate the angular frequency
Using formula of angular frequency

Put the value into the formula


We need to calculate the magnitude of the acceleration of the tip of the minute hand of the clock
Using formula of acceleration

Put the value into the formula


Hence, The magnitude of the acceleration of the tip of the minute hand of the clock
.
Based on your problem where as ask for the distance of the ball drop between the pitchers mound and the home plate and with a given of the speed of ball is 43m/s and the homeplates is 60.6ft away. Based on my step by step procedure and also considering the value of gravity by 9.8m/s^2 i came up with the distance of 144m away