Answer:
Mary will have to wait for 63.2 seconds
Explanation:
Time required for the apple to drop from a height of 17.0 m above the ground to 1.65 m above the ground is given by the formula below:
t = √2h/g where h is height through which the object falls, g is acceleration due to gravity
h = 17.0 - 1.65 = 15.35 m
g = 9.8 m/s²
t = √(2 * 15.35/9.8)
t = 1.77 s or approximately 1.8 s
Time taken for bill to get to the point below Mary's window is given below;
time taken = distance/velocity
distance = 130 m; velocity = 2.0 m/s
time taken by Bill = 130/2.0 = 65 s
Therefore, Mary will have to wait for (65 - 1.8) s = 63.2 seconds
ANSWER
My answer is in the photo above
Answer:
The time constant τ = L/R represent the time requiered for the curent to get value of 63 % of its maximun value
Explanation:
In a circuit RL ( serie circuit with a resistor R and the inductor L ) when a voltage is applied the inductor will have a reaction, such reaction consist in the creation of an electromotive force which will prevent the current to get its maximun value. The time constant which in the case of an inductor is
τ = L/R , represent the time requiered for the crrent to be 63 % of its final value
The kinetic energy of an object is given by:
where m is the mass of the object and v its speed. The ball in this problem has a mass of m=0.2 kg and a kinetic energy of K=40 J, so we can rearrange the previous equation to find its speed:
