Trusted since 2008
LoginRegister
Study resources on Kenyaplex

Get ready-made curriculum aligned revision materials

Exam papers, notes, holiday assignments and topical questions – all aligned to the Kenyan curriculum.

Browse exam papers
Or go directly to:
Class notes Holiday assignments Topical questions Other resources

A man uses an inclined plane to lift a 81kg mass through a vertical height of 1.0m. Given that the angle of inclination of the...

A man uses an inclined plane to lift a 81kg mass through a vertical height of 1.0m. Given that the angle of
inclination of the plane is 300 and its efficiency is 75%, determine:
a) The effort needed to move the load up the inclined plane at a constant velocity.
b) The workdone against friction in raising the mass through the height of 1.0m.

Answers

Moraa
a) The effort needed to move the load up the inclined plane at a constant velocity.
V.R=1/sin 30 =2
Therefore, (M.A/2)*20=75
M.A= (2*75)/20 =3/2
3/2 = 82N/effort
Effort= (82*2)/3 =540N
b) The workdone against friction in raising the mass through the height of 1.0m.
Work input=effort*effort distance = (540*4)/sin 30 =4320J
Work output=load*load distance= 81*2*4= 3240J
Therefore, workdone against friction= 4320-3240= 1180J
Moraa orina answered the question on April 9, 2018 at 16:54

Answer Attachments

Next: A machine whose velocity ratio is 8 is used to lift a load of 300N. The effort required is 60N. calculate: a) The mechanical advantage of...

Previous: . A driving gear having 25teeth engages with a second gear with 20teeth. A third gear with 30 teeth on the same shaft as the...

View more Physics Questions and Answers  |  Return to Questions Index

Exams With Marking Schemes

Related Questions