Physics Test 1 Part 2
The density of a solid object is defined as the ration of the mass of the object to its volume. The dimension of the density is...
[M][L]^-3
The block of mass m is at rest on an inclined plane that makes an angle θ with the horizontal. The force of static friction must be such that...
f = mg sinθ
An object is moving with constant velocity. What is the net force of the object?
0
The sum of two vectors has the greatest magnitude when the angle between these two vectors is...
0°
A force of 120 N is applied to an object whose mass is 0 kg. The object's acceleration is...
3600 m/s^2
An American football field, including end zones, is 360 feet long and 160 feet wide. What is its area in square meters?
5,350 square meters.
Four students measure the mass of an object, each using a different scale. They record the results as follows: 49.06, 49, 50, 49.1, 49.061. Which scale is the least precise?
50
An ant walks down the surface of a ball. f the ant begins to slip when the normal force is less than one-third of the ant's weight, at what angle, measured from the top of the ball, does the ant begin to slip?
70.5°
A 4.00-kg block rests on a 30.0° degree incline. If the coefficient of static friction between the block and the incline is 0.700, with what magnitude force must a horizontal force act on the block to start it moving up an incline?
84.1 N
A scalar quantity is defined as...
A quantity that is specified by a numerical value only.
An object rests on an inclined surface. If the inclination of the surface is made steeper, what does the normal force on the object do?
Decrease
The area under a curve in a velocity versus time graph gives...
Displacement
A ball is thrown up into the air. Neglect air resistance. When it is rising and reaches half of its maximum height, the net force acting on it is...
Equal to its weight.
Two athletes jump straight up. John has twice the initial speed of Harry. Compared to Harry, John stays in the air...
Four times as long.
A rock is thrown from ground level at some angle above the horizontal with a certain velocity. It reaches its highest point and starts falling down. What is the magnitude of the velocity of the rock right before it hits the ground?
It is equal to the magnitude of it initial velocity.
When a football in a field goal attempt reaches its maximum height, how does its speed compare to its initial speed?
It is less than the initial speed.
If the initial speed of a projectile is doubled...
Its range will quadruple.
A block of mass M slides down a frictionless plane inclined at an angle θ with the horizontal. The normal reaction force exerted on the plane of the block is...
Mg cosθ
For general projectile motion, the vertical component of a projectile's acceleration...
Remains a non-zero constant.
What does the word "normal" mean in the phrase "normal force"?
The component of the force exerted by a surface perpendicular to the surface.
If the acceleration vector of an object is directed anti-parallel to the velocity vector, then...
The object is slowing down.
At a given instant, the acceleration of a certain particle is zero. This means that...
The velocity is not changing in that instant.