Ch.5 Physics Kahoot
an object moves at a constant velocity of 12m/s to the southwest for an interval of 30s. Halfway through this interval, what is the magnitude of its instantaneous velocity?
12m/s
In mechanics physicists use 3 basic quantities to derive additional quantities. Mass is one of the 3 quantities. What are the other two?
Length and time
the figure shows a block on an inclined plane. What is the expression for the normal force acting on the block? (PIC)
MgcosO
When an object is dropped from a tower, what is the effect of the air resistance as it falls?
None of the above choices are valid
Which of the following is not true about potential energy?
Potential energy has direction
2 baseballs are released at the same time. one is dropped from rest and the other is given an initial horizontal velocity. Which of the following is not true? Ignore atmospheric drag
The horizontal component of velocity increases at a greater rate than the vertical component of velocity for both while they are both in the air
In a two dimensional Cartesian coordinate system the x-component of a given vector is equal to that vector's magnitude multiplied by which trigonometric function, with respect to the angle between vector and x-axis?
cosine
which of the following is an example of a nonconservative force
friction
The unit of power, watt, is dimensionally the same as
joule/second
The SI units for k, the spring constant, are equivalent to
kg/s^2
which of the following is that form of energy associated with an object's motion?
kinetic
a box slides across a floor and comes to rest. The work done by the frictional force on the box is
negative
the unit of work, joule, is dimensionally the same as
newton*meter
what forces are included in a free body diagram for an object
only the forces acting on the object
a suitcase is on a horizontal conveyor belt moving at speed v. The work done by the frictional force on the suitcase is
positive
which of the following is that form of energy associated with an object's location in a conservative force field?
potential
The rate at which work is done is equivalent to which of the following?
power
if we know an object is moving at constant velocity we may assume
the net force acting on the object is zero
Two blocks are released from the top of a building. One falls straight down while the other slides down a smooth ramp. If all friction is ignored, which one is moving faster when it reaches the bottom?
they both will have the same speed
in the terminology a 500N block, the 500N refers to the blocks
weight
The area under the force vs. displacement curve represents
work
