Answer: F = 102141N
Explanation: <em><u>Newton's 2nd Law</u></em> states that a force can change the motion of a body. The relation is given by
F = m.a
whose units are:
[F] = N
[m] = kg
[a] = m/s²
Jenny's car, at the moment of the break, had acceleration:


a = 78.57 m/s²
Then, Force is
F = 1300*78.57
F = 102141 N
<u>Jenny's car experienced a force of </u><u>magnitude 102141N.</u>
Answer:
Part a)
a = -9.81 m/s/s
Part b)
v = 0
Part c)
v = 9.81 m/s
Part d)

Explanation:
Part a)
During the motion of ball it will have only gravitational force on the ball
so here the acceleration of the ball is only due to gravity
so it is given as

Part b)
As we know that ball is moving against the gravity
so here the velocity of ball will keep on decreasing as the ball moves upwards
so at the highest point of the motion of the ball the speed of ball reduce to zero

Part c)
We know that the total time taken by the ball to come back to the initial position is T = 2 s
so in this time displacement of the ball will be zero



Part d)
at the maximum height position we know that the final speed will be zero
so we will have

here we have


Pacemaker........................................................
GPE = mgh (for objects close to earth where g can be considered to be constant) Where m is the mass, g is the acceleration due to gravity (which the question has told us to assume is 10ms^-2), and h is the height of the object.
Substituting the values in:
GPE = 70*10*10 = 7000J