Suppose you push a hockey puck of mass m across frictionless ice for a time 1.0 s, starting from rest, giving the puck speed v after traveling distance d. you repeat the experiment with a puck of mass 2m.

a. how long will you have to push for the puck to reach the same speed v?

b. how long will you have to push for the puck to travel the same distance d?

Case 1 :

let the force of push in both cases be "F"

m = mass of puck

acceleration of the puck is given as

a = F/m

t = time of push = 1 sec

d = distance traveled

v = speed gained

v₀ = initial speed = 0 m/s

Using the equation ,

v = v₀ + a t

v = 0 + (F/m) (1)

v = F/m

distance traveled is given as

d =  v₀ t + (0.5) a t²

d = (0)(1) + (0.5) (F/m) (1)²

d = F/(2m)

Case 2 :

a)

when the mass of puck is "2m"

acceleration is given as

a' = F/(2m)

t'= time of push = ?

d' = distance traveled = d = F/(2m)

v' = speed gained = v =  F/m

v'₀ = initial speed = v₀ = 0 m/s

Using the equation ,

v' = v'₀ + a' t'

(F/m) = 0 + (F/(2m)) t'

t' = 2 sec

b)

distance traveled is given as

d' =  v'₀ t' + (0.5) a' t'²

F/(2m) = (0) t'  + (0.5) (F/(2m)) t' ²

t' = 2 sec

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2