Physics SGO

Neglecting the effect of air resistance a stone dropped off a 175-m high building lands on the ground in... a. 3 s b. 4 s c. 6 s d. 18 s e. 36 s

c. 6 s

The inertia of a body tends to cause the body to... a. speed up b. slow down c. resist any change in its motion d. fall towards Earth e. decelerate due to friction

c. resist any change in its motion

A boy holds a 40-N weight at arm's length for 10s. His arm is 1.5m above the ground. The work done by the force of the boy on the weight while he is holding it is... a. 0 b. 6.1 J c. 40 J d. 60 J e. 90 J

a. 0

A 400-N steel ball is suspended by a light rope from the ceiling. The tension in the rope is... a. 400-N b. 800-N c. zero d. 200-N e. 560-N

a. 400-N

As a rocket is accelerating vertically upward at 9.8 m/s² near Earth's surface, it releases a projectile. Immediately after release the acceleration (in m/s²) of the projectile is... a. 9.8 down b. 0 c. 9.8 up d. 19.6 up e. none of the above

a. 9.8 down

A ball is in free fall. Its acceleration is... a. downward during both ascent and descent b. downward during ascent and upward during descent c. upward during ascent and downward during descent d. upward during both ascent and descent e. downward at all times except at the very top, when it is zero

a. downward during both ascent and descent

Which of the following quanitites is NOT a vector? a. mass b. displacement c. weight d. acceleration e. force

a. mass

You stand on a spring scale on the floor of an elevator. Of the following, the scale shows the highest reading when the elevator... a. moves upward with increasing speed b. moves upward with decreasing speed c. remains stationary d. moves downward with increasing speed e. moves downward at constant speed

a. moves upward with increasing speed

A brick slides on a horizontal surface. Which of the following will increase the magnitude of the friction force on it? a. putting a second brick on top b. decreasing the surface area of contact c. increasing the surface area of contact d. decreasing the mass of the brick e. none of the above

a. putting a second brick on top

Velocity is defined as... a. rate of change of position with time b. position divided by time c. rate of change of acceleration with time d. a speeding up or slowing down e. change of position

a. rate of change of position with time

Which of the following is a scalar quantity? a. speed b. velocity c. displacement d. acceleration e. none of these

a. speed

Which one of the following statements is correct for an object released from rest? a. the average velocity during the first second of tiem is 4.9 m/s b. during each second the object falls 9.8 m c. the acceleration changes by 9.8 m/s² every second d. the object falls 9.8m during the first second of time e. the acceleration of the object is porportional to its weight

a. the average velocity during the first second of time is 4.9 m/s

The unit of force called the newton is... a. (9.8 kg)(m/s²) b. (1kg)(m/s²) c. defined by means of Newton's third law d. 1 kg of mass e. 1 kg of force

b. (1kg)(m/s²)

A baseball is thrown vertically into the air. The acceleration of the ball at its highest point is... a. zero b. g, down c. g, up d. 2g, down e. 2g, up

b. g, down

An object is shot vertically upward. While it is rising... a. its velocity and acceleration are both upward b. its velocity is upward and its acceleration is downward c. its velocity and acceleration are both downward d. its velocity is downward and its acceleration is upward e. its velocity and acceleration are both decreasing

b. its velocity is upward and its acceleration is downward

A feather and a lead ball are dropped from rest in vacuum on the Moon. The acceleration of the feather is... a. more than that of the lead ball b. the same as that of the lead ball c. less than that of the lead ball d. 9.8 ms² e. zero since it floats in a vacuum

b. the same as that of the lead ball

Mass differs from weight in that... a. all objects have weight byt some lack mass b. weight is a force and mass is not c. the mass of an object is always more than its weight d. mass can be expressed only in the metric system e. there is no difference

b. weight is a force and mass is not

Acceleration is defined as... a. rate of change of position with time b. speed divided by time c. rate of change of velocity with time d. a speeding up or slowing down e. change of velocity

c. rate of change of velocity with time

A bullet shot horizontally from a gun... a. strikes the ground much later than the one dropped vertically from the same point and the same instant b. never strikes the ground c. strikes the ground at approximately the same time as one dropped vertically from point at the same instant d. travels in a straight line e. strikes the ground much sooner than the one dropped from the same point at the same instant

c. strikes the ground at approximately the same time as one dropped vertically from the same point at the same instant

A freely falling body has a constant acceleration of 9.8 m/s². This means that... a. the body falls 9.8 m each second b. the body falls 9.8 m during the first second only c. the speed of the body increases by 9.8 m/s during each second d. the acceleration of the body incrase by 9.8 m/s² during each second e. the acceleration of the body decreases by 9.8 m/s² during each second

c. the speed of the body increases by 9.8 m/s during each second.

An object moving in a circle at constant speed... a. must have only one force acting on it b. is not accelerating c. is held to its path by centrifugal force d. has an acceleration of constant magnitude e. has an acceleration that is tangent to the circle

d. has an acceleration of constant magnitude

Which of the following five quantities is NOT an expression for energy? Here m is a mass, g is acceleration due to gravity, h and d are distances. F is a force, v is a speed, a is an acceleration, P is power, and t is time. a. mgh b. F d c. 1/2mv² d. ma e. P t

d. ma

Acceleration is always in the direction... a. of the displacement b. of the initial velocity c. of the final velocity d. of the net force e. opposite to the frictional force

d. of the net force

A stone thrown from the top of a tall building follows a path that is... a. circular b. made of two straight line segments c. hyperbolic d. parabolic e. a straight line

d. parabolic

A newton is the force... a. of gravity on a 1kg body b. of gravity on a 1g body c. that gives a 1g body an acceleration of 1 cm/s² d. that gives a 1kg body an acceleration of 1m/s² e. that gives a 1kg body an acceleration of 9.8m/s²

d. that gives a 1kg body an acceleration of 1m/s²

An object dropped from the window of a tall building hits the ground in 12 s. If its acceleration is 9.8 m/s², the height of the window above the ground is... a. 29.4m b. 58.8m c. 118m d. 353m e. 706m

e. 706 m.

Which of the following is a vector quantity? a. mass b. density c. speed d. temperature e. none of these

e. none of these

A car travels east at constant velocity. The net force on the car is... a. east b. west c. up d. down e. zero

e. zero