Question

1. A kid is pulling on a lawnmower with an applied force FA that is 30° with respect to the horizontal. Which statement is true about the normal force acting on the lawnmower? (5 pts) A. The normal force acting on the block N = 0, 300 B. The normal force acting on the block N < mg. C. The normal force acting on the block N > mg. D. The normal force acting on the block N = mg. E. None of the above 2. I lower an object of mass 50 kg (initially at rest) vertically downwards by h = 2 meters while applying a upward force of FN = 30 newtons. Which of the following collections of work-energy equations is correct? a. AE = (30)(2) APE = (500)(2) AKE = (500 – 30)(2) b. AE = (30)(2) APE = -(500)(2) AKE = -(500 – 30)(2) c. AE =- (30)(2) APE = -(500)(2) AKE = (500 - 30)(2) d. AE = (30)(2) APE = -(500)(2) AKE = (500 - 30)(2) e. AE = (30)(2) APE = -(500)(2) AKE = 0 NOTE: All energy changes above are in joules. A block of mass m is sliding across rough inclined plane, as shown in the figure. Which is a true statement about the normal force acting on the block? a. It does positive work on the block whether or not the block is sliding up or down the plane b. It does negative work on the block whether or not the block is sliding up or down the plane c. It does negative work on the block if the block is sliding up the plane but positive work if the block is sliding down the plane d. It does negative work on the block if the block is sliding down the plane but positive work if the block is sliding up the plane e. It does no work on the block

Answer 1

(1) Normal force = mg -Fahr 30° .:(N<mg {bo option is correct 2) work done as (Net force). displacements AKE > (mg -F) d AKF [8oxo) - 30] d SKE » [500 - 30] [2] APE = – ngh % -1600)(2) DE = 30 (2) Nolobtion is correct 6 (1) It does no work because work done -FNX displacement & Costo o

Please ask your doubts or queries in the comment section below.

Please kindly upvote if you are satisfied with the solution.

Thank you.