A child pulls a wagon 3.0 m using a force of 55 N at an angle 35° above horizontal. The force of friction on the wagon is 12 N. Calculate the net work done on the wagon

99J

Explanation:

distance s = 3 m

The force is given at an angle .Cos it to get horizontal and sin it get vertical

force f  horiz = 55N * cos 35 = 45 N

angle is 35

Friction F = 12N

we need to take resultant force as work is done after every force does its contribution.We sub pulling with friction to get resultant

W= (f-F) S

W= 45-12 * 3

W= 33*3

W= 99J

answer: 802.3 kilo joules of energy represents 191.75 kilo calorie of energy.

explanation:

energy released during combustion of one mole methane = 802.3 kilo joules

if 1 kilo joule = 0.239006   kilo calorie

then ,802.3 kilo joule will be = 802.30.239006 kilo calorie

802.3 kilo joule = 191.75 kilo calorie

hence, the energy in kilo calorie is 191.75 kilo calorie.

3.2x10^7