Asuspicious looking car (a) travels along a road at a constant velocity of 13.3m/s. as it passes a parked, stationary police car (p), the police car accelerates from rest at 4m/s 2 in pursuit. the police car continues to accelerate until it reaches a velocity of 17.3m/s. (a)how long does it take, from the moment the police car starts moving, for the police car to pull alongside the pursued car? (b)how far has the police car travelled at this instant?

a) 9.4 sec

b) 125.02 m

Explanation:

a)

For the police car :

v₀ = initial velocity of the police car = 0 m/s

a = acceleration of the car = 4 m/s²

v' = final constant velocity gained by police car = 17.3 m/s

t' = time taken to attain the final constant velocity

using the equation

v' = v₀ + a t'

17.3 = 0 + (4) t'

t' = 4.325 sec

d' = distance traveled by the police car while accelerating

distance traveled by the police car while accelerating is given as

d' = v₀ t' + (0.5) a t'²

d' = (0) (4.325) + (0.5) (4) (4.325)²

d' = 37.4 m

Consider the motion the suspicious looking car for the time when the police car accelerate:

v = velocity of suspicious looking car = 13.3 m/s

t' = time taken to accelerate = 4.325 sec

d = distance traveled by suspicious looking car = v t' = (13.3) (4.325) = 57.5 m

t = time after which the suspicious car is caught

for the police car to catch the suspicious car

d' + v' (t - t') = v t

37.4 + (17.3) (t - 4.325) = 13.3 t

t = 9.4 sec

b)

D = distance traveled by police car = distance traveled by suspicious car = v t

D = 13.3 x 9.4

D = 125.02 m  

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz

0.863333

86%

hope this