AP Physics Midterm Review

Rate at which an object rotates

Define angular velocity

Acceleration

What does the slope of a Velocity vs. Time graph indicate?

At rest

What does this Position vs. Time graph show?

Constant Acceleration

What does this Position vs. Time graph show?

Constant Velocity

What does this Position vs. Time graph show?

At rest

What does this Velocity vs. Time graph show?

8.82kgm/s

A 0.42kg soccer ball moving at 9m/s to the west is kicked and now moves at 12m/s to the east. What was the impulse delivered to the ball by the soccer player?

P=147W

A 10kg grate is lifted straight up at a constant speed a distance 3m. It takes 2s to lift the crate. What power is produced lifting the crate?

W=26993.25J

A 1350kg car accelerates from 2.5m/s to 6.8m/s. How much work is done on the car to change its speed?

A) KE=52.2J B) V=48.8m/s

A 47.0-g golf ball is driven from the tee with an initial speed of 52.0 m/s and rises to a height of 24.6 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 8.0 m below its highest point?

m=0.499kg

A ball is attached to a string and whirled in a circle at a speed of 7m/s. The string is 0.6m long and the tension in the string is 40.8N. What is the mass of the ball?

Vo=39m/s

A ball is thrown vertically upward, which is the positive direction. A little later it returns to its point of release. The ball is in the air for a total time of 8.0 s. What is its initial velocity? Neglect air resistance.

Vf=7.75m/s

A ball rolling at 6m/s slides of a table and strikes the floor 0.5s later. What is the speed on impact?

A) x=1.35km θ=20.85° N of W B) V=0.54km/h θ=20.85° N of W

A bird watcher meanders through the woods, walking 0.50 km due east, 0.75 km due south, and 2.15 km in a direction 35.0° north of west. The time required for this trip is 2.50 h. Determine the magnitude and direction (relative to due west) of the bird watcher's (a) displacement and (b) average velocity. Use kilometers and hours for distance and time, respectively.

W=-8.49N

A bow on a frictionless surface accelerates a 3m/s² when 2.6N force acts on it. What is the weight of the box?

868.39m 35.54° N of E

A boy walks 500m north, turns east and walks 710m. What is his resultant displacement?

Vf=19.8m/s

A car has an initial velocity of 15m/s, and accelerates at 2m/s² for 2.4 seconds. What is the final velocity of the car?

x=39.2m

A car is traveling at 20.0 m/s, and the driver sees a traffic light turn red. After 0.530 s (the reaction time), the driver applies the brakes, and the car decelerates at 7.00 m/s2. What is the stopping distance of the car, as measured from the point where the driver first sees the red light?

ω=2.62rad/s

A ceiling fan makes 25 revolutions in 1 minute. Find angular velocity of the ceiling fan.

Fk=7.5N

A horizontal force +30N accelerates a 15kg mass from rest at 1.5m/s². What frictional force acts on the 15kg mass?

ω=53.85rad/s

A piece of gum stuck to a bike tire has a tangential speed of 14m/s. What is the angular speed of the tire if the diameter is 52cm?

A) T=914.266N B) T=822N

A rescue helicopter is lifting a man (weight = 822 N) from a capsized boat by means of a cable and harness. (a) What is the tension in the cable when the man is given an initial upward acceleration of 1.10 m/s2? (b) What is the tension during the remainder of the rescue when he is pulled upward at a constant velocity?

t=3.96s

A soccer ball is kicked and has an initial velocity of 22m/s at 50° about the horizontal. How long does the ball stay in the air?

Outer edge

As a CD rotates, which point has a greater linear speed, a point on the edge of the CD or a point midway between the center and the edge?

θ=39°

Before attempting this problem, review Examples 7 and 8. Two curves on a highway have the same radii. However, one is unbanked and the other is banked at an angle θ A car can safely travel along the unbanked curve at a maximum speed v0 under conditions when the coefficient of static friction between the tires and the road is μs = 0.81. The banked curve is frictionless, and the car can negotiate it at the same maximum speed v0. Find the angle θ of the banked curve.

A) 60m/s B) 33m/s

Car A moves east at 33m/s. Car B moves west at 27m/s. Car C is at rest on the side of the road. What is the speed of A relative to B? What is the speed of A relative to C?

Time rate of change of angular velocity

Define angular acceleration

The angle through which an object rotates

Define angular displacement

Vx=constant at A, B, C Vy=0 at B and (-) at A and (+) at C (but equal at A and C)

Describe the velocity and acceleration of the ball at points A, B, and C

...

Draw a diagram of a box sliding down an incline plane. Show all forces acting on the box

∑F=39.05N at 63.63° above the horizon

Find the net force acting on the box below

Mass is the same

How does the mass of an object on the moon compare to the mass of the same object on earth?

Weight is less on the moon (no gravity)

How does the weight of an object on the moon compare to the weight of the same object on earth?

Gravitational force would be 4x greater

If the distance between the earth and moon were cut in half, what would happen to the force of gravity between the earth and moon?

They will get to the water at the same time because of gravity

Suzy is standing on a bridge and has two identical rocks. She throw one horizontally just as she drops the other. Which rock will get to the water below the bridge first?

A) 7.7m/s B) 7.7m/s C) 4.0

The drawing shows two boxes resting on frictionless ramps. One box is relatively light and sits on a steep ramp. The other box is heavier and rests on a ramp that is less steep. The boxes are released from rest at A and allowed to slide down the ramps. The two boxes have masses of 11 and 44 kg. If A and B are 4.5 and 1.5 m, respectively, above the ground, determine the speed of (a) the lighter box and (b) the heavier box when each reaches B. (c) What is the ratio of the kinetic energy of the heavier box to that of the lighter box at B? w0395

Perpendicular force does not do any work (θ=90°) Parallel force does to work

Two forces act on an object. One is parallel to the displacement and the other is perpendicular. Do both forces do work on the object?

Va=7694.5m/s

Two satellites are in circular orbits around the earth. The orbit for satellite A is at a height of 360 km above the earth's surface, while that for satellite B is at a height of 720 km. Find the orbital speed for each satellite.

To the center

What direction does centripetal force act as an object travels in a circular path?

Displacement

What does the area under the Velocity vs. Time graph indicate?

Velocity

What does the slope of Position vs. Time graph indicate?

Constant Acceleration

What does this Velocity vs. Time graph show?

Constant Velocity

What does this Velocity vs. Time graph show?

The product of the average force, F, and the time, ∆t, during which the force acts

What is impulse?

A conservative force is when work a force does is independent of the path, while a nonconservative force is when work a force does on an object between a point depends on the path

What is the difference between a conservative force and a nonconservative force?

V=6.32m/s θ=18.4° N of E

You are in a hot-air balloon that, relative to the ground, has a velocity of 6.0 m/s in a direction due east. You see a hawk moving directly away from the balloon in a direction due north. The speed of the hawk relative to you is 2.0 m/s. What are the magnitude and direction of the hawk's velocity relative to the ground? Express the directional angle relative to due east.