Tuesday

October 21, 2014

October 21, 2014

Posted by **Anonymous** on Wednesday, May 5, 2010 at 3:39am.

1b) how large is the force with which the block pulls on the donkey?

1c) how large is the normal force?

1d) what is the force that the donkey of mass M,applies on the incline?

1e) if the rope that ties the box to the donkey is cut, what will the acceleration of the box be?

- science -
**drwls**, Wednesday, May 5, 2010 at 8:18am1a) The equation you will need to solve this problem is F = ma.

The "F" part of the equation is the net force, which is the sum of the force applied by the donkey (F1), the weight component up the hill (F2) and the friction force (F3).

F = F1 - F2 - F3 = m a

= 100 kg*0.2 m/s^2 = 20 N

F2 = m g sin30 = 980 * (0.5) = 490 N

The friction force is

F3 = m g cos 30*Uk = 255 N

where Uk is the kinetic friction coefficient. 0.3 in this case.

Solve for F1.

1b) Think: Newton's Third law.

1c) mg cos 30

1d) M is now the donkey's mass. It applies both a normal force (M g sin 30) and a friction force (M a - F1) to the incline. They don't tell you the value of M

1e) a = [m g sin 30 - m g cos 30 Uk]/m

= g(0.5 - 0.26) = ___

**Answer this Question**

**Related Questions**

physics - a blockof mass 100 kg tied to a donkey that moves with constant ...

physics - Donkey experiencing a gravitational force of 2500 N is trying to pull ...

Linear Algebra - Two prospectors are pulling on ropes attached around the neck ...

Physical Science - A donkey pulls a cart(c) with a mass of 240kg, attached to a ...

Physics - Three people pull simultaneously on a stubborn donkey. Jack pulls ...

physics - There is a block on top of an incline plane. The incline is going down...

physics - A block of weight w = 25.0 N sits on a frictionless inclined plane, ...

5th grade math - A donkey and a mule were carrying bags of corn. If the mule ...

Physics - Three people pull simultaneously on a stubborn donkey. Jack pulls ...

Physics - A block of weight = 25.0 N sits on a frictionless inclined plane, ...