Exam 5: Force and Motion

A heavy wooden block is dragged by a force along a rough steel plate, as shown below for two cases.The magnitude of the applied force is the same for both cases.The normal force in (ii), as compared with the normal force in (i)is:

A 25-kg crate is pushed across a frictionless horizontal floor with a force of 20 N, directed 20°below the horizontal.The acceleration of the crate is:

A box is on a scale.In which of these situations will the scale reading NOT equal the weight of the box?

A constant force of 8.0 N is exerted for 4.0 s on a 16-kg object initially at rest.The change in speed of this object will be:

A 32-N force, parallel to the incline, is required to push a certain crate at constant velocity up a frictionless incline that is 30°above the horizontal.The mass of the crate is:

A force of 1 N is:

Two blocks are connected by a string and pulley as shown.Assuming that the string and pulley are massless, the magnitude of the acceleration of each block is:

A sled is on an icy (frictionless)slope that is 30°above the horizontal.When a 40-N force, parallel to the incline and directed up the incline, is applied to the sled, the acceleration of the sled is 2.0 m/s², down the incline.The mass of the sled is:

An object placed on an equal-arm balance requires 12 kg to balance it.When placed on a spring scale, the scale reads 12 kg.Everything (balance, scale, set of weights and object)is now transported to the Moon where free-fall acceleration is one-sixth that on Earth.The new readings of the balance and spring scale (respectively)are:

Mass differs from weight in that:

Which of the following is a correct statement of Newton's first law?

A feather and a lead ball are dropped from rest in vacuum on the Moon.The acceleration of the feather is:

A 5-kg block is suspended by a rope from the ceiling of an elevator that accelerates downward at 3.0 m/s².The tension force of the rope on the block is: