A boy is pulling a 150 kg crate with a force of 1150 N. If the crate experiences a frictional force of 490 N, find: a) The acceleration of the crate.

b) The normal force acting on the crate.

First, let's find the resultant, and applicate 2nd law of Newton using the resultant, so:

R = ma

F - Ff = ma

Data:

F = Force = 1150 N

Ff = Friction force = 490 N

m = Mass = 150 kg

a = Aceleraction = ?

Replacing according our data:

1150 N - 490 N = 150 kg * a

660 N = 150 kg * a

660 N / 150 kg = a

a = 4,4 m/s²   ← Aceleration of the object

The normal force IS NOT the resultant force, the normal force's the force between the ground and the object, in another words, is the weight of the object, and for the weight:

w = mg

w = 150 kg * 10 m/s²

w = 1500 N   ← Normal force between object and ground.

the answer would most likely be c, because if it's a comical piece of information, it may likely not be true, if it's a site that allows anybody to edit the content, it could mean a five year old is typing the info, and if it's a tv show produced by a celeb, it may have a biased opinion.

talk back to him about the sport and show him your expertise or leave the room