A person lifts a 4.8 kg cement block a vertical distance of 1.4 m and then carries the block horizontally a distance of 7.1 m.
The acceleration of gravity is approximately 9.81 m/s^2
Determine the work done by the person in the proscess. Answer must be in units of joules.
i know how to find the work done by each seperately but when i added the two, the site said my answer was wrong.
can someone explain to me how go about solving this?
2006-11-14 14:22:06 · 2 answers · asked by wish1oh1 1 in Science & Mathematics ➔ Physics
Don't add the two. Only the vertical distance counts in determining work because only in lifting the block did you move it against the force of gravity.
2006-11-14 14:35:40 · answer #1 · answered by Jim R 2 · 0⤊ 0⤋
work= force x distance x cosa now, for the 1st case the person is carryin the weight vertically so a=90, cos90=0, therefore work done in 1st case is zero....( always remember that work done vertically in physics is zero as cos90=0). now in 2nd case workk= 4.8 x 9.81 x 7.1 x 1(since cos0=0)=334.3248 Nm or joules
2006-11-14 14:39:26 · answer #2 · answered by omarkabeer 1 · 0⤊ 0⤋