Aboy and his skateboard have a combined mass of 65 kg. what is the speed of the boy and skateboard if they have a momentum of 275 kg • ? 0 m/s 0.24 m/s 4.2 m/s 8.5 m/s

Answer : Speed is 4.2 m/s

Explanation :

The combined mass of the boy and the skateboard is 65 kg

The momentum of the boy and the skateboard is 275 kg m/s

The momentum is given by:

p = m v

where m is the combined mass of boy and the skateboard.

v is the speed of both boy and the skateboard.

The speed of the boy and the skateboard is 4.2 m/s

So, the correct option is (C).

Hence, this is the required solution.

  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

f=ma newton

f=100x2.5=250n