Vector is perpendicular to x axis or i component.
Hence i component is 0
j component is 63.5
Answer:
The force needed to slow down the car is, F = 67.5 N
Explanation:
Given data,
The mass of the car, m = 15 kg
The initial velocity of the car, V = 60 m/s
The final velocity of the car, v = 15 m/s
The time period of deceleration, t = 10 s
The difference in the momentum of the car is,
mV - mv = 15(60 - 15)
= 675 kg m/s
The rate of change in momentum of the car gives the force acting on it.
F = (mV - mu) / t
Substituting the values,
F = 675 / 10
= 67.5 N
Hence, the force needed to slow down the car is, F = 67.5 N
Answer:
0.25 gram of neptunium is remaining
Explanation:
First we calculate the no. of half lives passed. For that we have formula:
n = t/T
where,
n = no. of half lives passed = ?
t = total time passed = 8 days (From Monday noon to Tuesday noon of following week)
T = Half Life Period = 2 days
Therefore,
n = 8 days/2 days
n = 4
Now, for the remaining mass of neptunium, we use the formula:
m = (mi)/(2)^n
where,
mi = initial mass of neptunium = 4.00 grams
m = remaining mass of neptunium = ?
Therefore,
m = 4 grams/2⁴
<u>m = 0.25 gram</u>
