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If the average speed of a spacecraft is 20, 000 miles/h, find the time needed for it to orbit the earth once. Assume that the spacecraft is orbiting 175 miles above the earth’s surface and that the radius of earth is 3963 miles.

Truck A travels at a constant speed of 50 miles/h on a straight road. Truck B travels at a constant speed of 70 miles/h in the same direction. Assume that both trucks start at the same point at the same time. How sooner will the truck B reach a place, which is 15 miles away? 

Truck A travels at a constant speed of 50 miles/h on a straight road. Truck B travels at a constant speed of 70 miles/h in the same direction. Truck A passes a gas station at 12 noon. Truck B passes the same gas station at 12:30 pm. At what time does truck B catch up with truck A? How far are the trucks from the gas station when this happens? 

A person moves in a straight-line path as shown in the diagram (refer to the answer to view the diagram). Find the average velocities in the following time intervals.

(a) Between t = 0 and 1.5 s
(b) Between t = 1.5 and 4.0 s
(c) Between t = 0 and 4.0 s
(d) Between t = 0 and 8.0 s 

mech1D-12

On a trip Amy has constant velocity of 89.0 km/hr except for 20 min rest. If average velocity is 77.0 km/hr how long does trip take?

mech1D-13

When coming to a stop, a vehicle leaves skid marks 80 m long on the highway. Assuming a deceleration of 7.50 m/s², find the speed of the car just before braking.

Two players are running towards each other. They are 37 m apart. If one is accelerating from rest at 0.5 m/s² and the other was moving at 3.1 m/s and maintains his speed, how long until they crunch together?

mech1D-15

A person moves in a straight-line path as shown in the above diagram. Find the average velocities in the following time intervals. Find the instantaneous velocities at the following instances
(a) t = 1.0 s

(b) t = 3.0 s

(c) t = 4.5 s

(d) t = 7.0 s

 A 2-lb ball is thrown upward at 30ft/s from an origin 5-ft above the earth’s surface. Using for your positive reference a vertical y axis with its origin at 5ft, determine for the ball:

a) The maximum height in ft reached
b) The elapsed time of flight in seconds until its return to the origin
c) Its acceleration in ft/s² at the highest point
d) Its velocity vector at its return to the origin

 mech1D-17

The velocity of a 0.1kg particle along a horizontal X axis is given by: v(t)=(8t² -20)m/s, and at t=20s, x(20)=60m. Find the following for t=8s:

(a) The position of the particle in ft
(b) The velocity of the particle in ft/s
(c) The acceleration of the particle in ft/s²

1. The acceleration on the moon is 1/6 that of the earth. If a ball is tossed upward at an initial speed of 7 m/s, how high will it be above the surface of the moon before it starts to return?

2. The acceleration on the moon is 1/6 that of the earth. If a ball is tossed upward at an initial speed of 7 m/s, how long will it take to reach its highest point above the moon’s surface?

mech1D-19

1. Risking a huge fine, you decide to drop a rock off the edge of the Grand Canyon. If it takes 11 seconds for the stone to hit the first ledge, how far below you is the ledge?


2. While gift shopping, you accidentally knock a glass object off of a shelf 1.2 m above the floor. How fast is the object moving when it hits the floor?

1. A car, going 3.4 m/s travels north for 6.4 minutes. What is the car’s displacement?

2. Walking at a steady pace of 2.3 m/s, how long will it take Carl to take his evening walk, a distance of 2.1 Km?

3. John is coming home from Poland. If his non-stop flight from Warsaw to Washington DC takes 9 hours, 15 minutes to travel the entire 7597 Km distance, what is his average speed?

4. A car travels 59 m due east in 6 seconds. It then turns north, and travels for 7 seconds at a constant speed of 5.2 m/s. What is the final displacement of the car?

mech1D-21 

1. The acceleration on the moon is 1/6 that of the earth. If a ball is tossed upward at an initial speed of 7 m/s, how high will it be above the surface of the moon before it starts to return?

2. The acceleration on the moon is 1/6 that of the earth. If a ball is tossed upward at an initial speed of 7 m/s, how long will it take to reach its highest point above the moon’s surface?

3. Risking a huge fine, you decide to drop a rock off the edge of the Grand Canyon. If it takes 11 seconds for the stone to hit the first ledge, how far below you is the ledge?

4. While gift shopping, you accidentally knock a glass object off of a shelf 1.2 m above the floor. How fast is the object moving when it hits the floor?

mech1D-22

Elevator Problem:

The tension in a string holds a solid block of wood, with a density of 0.788 gm/cm³, below the surface of a liquid that has a density of 0.932 gm/cm³. The container is placed in an elevator that accelerates vertically upward at 11.6 m/s².
Determine the tension in the string if the volume of the wooden block is 33.7 cm³ and its height is 5.11 cm. Show all work, including a free body diagram.

Atwood Machine Problem:

A projectile was fired at an angle of 65 degrees with respect to the horizontal. It has an initial velocity of 60-km/h. When the

projectile was at the top of its trajectory, an internal explosion causes it to separate into 2 fragments of equal mass. One fragment falls straight down as though it was released from rest. How far from the launch point does the other fragment land?

Mech2D-2:

A hunter directly aims at a target that is on the same level as the hunter,120 m away. The bullet leaves the gun at a speed of 250 m/s. (1) By how much will it miss the target? (2) At what angle should the bullet be fired to hit the target? 

A bug moves in the x-y plane. At t = 0, it is at the origin and starts to move with a velocity of 0.01 m/s in the +y direction. Bug’s acceleration is given by: a = (0.5 i + 0.8 j) m/s^2 where i and j are unit vectors along x and y directions respectively. What is the bug’s speed when its x coordinate is 1 m?

A rock with an initial speed of 55 m/s was thrown at an angle θ with respect to the horizontal. If it lands 215 m

away on a level ground, (a) what are the two possible values of θ for which this result is achieved, (b) what are the

maximum heights reached for both of these possibilities?

A marble rolls off a table top with a speed of 5m/s. Tabletop is 1.6 m above the floor. Where will the marble hit the floor and what velocity components will it have just before it hits the floor?

A projectile is fired at an angle of 30.0° above the horizontal

with an initial speed of 60 m/s. How long does it take the projectile to reach the highest point in its trajectory?

A crate slides down a ramp that is at a 40° incline. The speed of the crate at the bottom would have been 3 times greater if there was no friction present. What is the coefficient of friction between the crate and the ramp?

Mech2D-9:

A ball is projected with an initial speed of 50 m/s at an

angle of 45° above the horizontal.
a) Find the distance the ball travels horizontally.
b) Find the maximum height of the ball during the flight.

According to the information given in the following image, what is the initial angle of inclination of the projectile? What is the direction of the final velocity? Show your work. (Image)

A 500 gram ball is dropped from a height of 50 m. When it hits the floor, it bounds off the floor and rises to a height 35 m. Assuming that the ball was in contact with the floor for a duration of 2.3 ms, find the average force experienced by the ball while in contact with the floor.

A person weighs 900 N on earth. What will be his weight on the Moon? What will be his weight on Jupiter? Acceleration of gravity on Moon and Jupiter is 1.63 and 25.9 m/s^2 respectively.

A bullet is fired from a rifle. It leaves the muzzle of the rifle with a speed of 400 m/s. What is the force acted upon the bullet during its travel through the 0.80 m barrel. Assume that the mass of the bullet is 5 grams and that the force is constant.

Two students pull a bookcase in two directions as shown in the figure. Find the resultant force on the bookcase. Find the acceleration of the bookcase if its mass is 600 kg.

A 50 kg carton is pulled up a hill inclined at 20^o with respect to the horizontal. Tow rope has a tension of 150 N. Assuming that the carton starts from rest from the bottom of the hill, find its speed when it has moved a distance of 100 m along the slope. Neglect any friction.

A mass m1 resting on a frictionless table is connected to a cable that passes over a pulley. The other end of the cable is connected to a mass of m2. Find the acceleration of the masses and the tension in the cable in terms of the given quantities. Assume that there is no friction between the pulley and the cable.  

newton-9

A crate with a weight of 300 N accelerates along a frictionless surface as the it is pulled with a force of F = 15.0 N as shown in the figure. What is the horizontal acceleration of the crate?

Momentum and Impulse 

(1) What acceleration does Jeff give his 0.48 Kg Physics book, when he accidentally knocks it off a table with an impulse of 2.3 Ns in 0.10 s?

(2) A force of 3420 N is applied to a 145 g baseball. If the baseball approaches the batter at 41.3 m/s and leaves at 44.2 m/s, how long was the bat in contact with the ball?

(3) Crash test dummies sometimes do not wear seat belts. If a 78 Kg dummy, in a car traveling at 53 Km/h, hits a concrete barrier and stops in 0.20 s, what is the force applied to the dummy?

(4) How much force is applied to a 76 Kg man’s legs when he jumps off a table 1.0 m above the
floor, if it takes 0.11 s for him to stop? (HINT: Remember your kinematic equations.)

1. Calculate the momentum of a car that is traveling east on I-80 at 32 Km/hr. The mass of the truck is 982 Kg.

2. If Peter backs his 28,000 Kg pick-up truck down his driveway at 1.75 m/s, what is the magnitude of the truck’s momentum?

3. Calculate the momentum of a 132 Kg person in a car traveling south on I-95 at 78 Km/hr.

4. What is the momentum of a 1.31 N helium balloon as it flies away at 3.51 m/s?

(student posted question)

A mass of 152 g collides with a stationary 132 g mass. If the collision is totally inelastic, calculate the final speed of the mass if the initial speed was 0.854 m/s.

A 2.30 Kg mass, moving at a speed of 4.21 m/s collides with an identical mass at rest. After the collision, the first mass moves at a 32° angle (to the left) and the second mass moves at a 58° angle (to the right). Calculate the speed of both masses after the collision.

Atwood Machine

Two masses hang from either side of a pulley (500 g, diameter = 35 cm) as shown. Find the acceleration of the system and the tensions in the cord. Find the tension on the codes.

Elevator Problem:

The tension in a string holds a solid block of wood, with a density of 0.788 gm/cm³, below the surface of a liquid that has a density of 0.932 gm/cm³. The container is placed in an elevator that accelerates vertically upward at 11.6 m/s².
Determine the tension in the string if the volume of the wooden block is 33.7 cm³ and its height is 5.11 cm. Show all work, including a free body diagram.

A woman rides a sled down a 10 m high frictionless slope. If she starts off with a speed of 6 m/s, what is her speed at the bottom of the hill?

A construction worker lifts a 30.0 kg wooden block tied to a rope from ground level to the roof and does 8.00 kJ of work. What is the height of the roof? Assume that the speed of the block remains the same.

A student pulls a table with a force of 40 N directed at an angle of 20o downward from the horizontal. Find the work done by the student as she moves down a 100 m length of floor.

One end of a rope of length 12.0 m is fixed to a tree limb above. A monkey, whose mass is 8.0 kg, holds onto the free end of the rope and swings back and forth. Eventually, he gets the rope to swing enough that he can reach a branch when the rope makes a 60o angle with downward vertical. How much work is done against the force of gravity?

A 80 kg baseball player slides into second base when moving at a speed of 5.0 m/s. The coefficient of friction between him and the ground is 0.73. His speed as he reaches the second base is zero. (a) How much mechanical energy is lost due to friction? (b) How far does he slide?

A 50.0 kg wooden box was pushed with a horizontal force of 140 N for a distance of 6.00 m on a rough horizontal surface. If the box moves at a constant speed, find (a) the work done by the force and (b) the coefficient of kinetic friction.

A traveler pulls his 60.0 N carry-on bag a distance of 250 m along an airport floor at a constant speed with a force of 50.0 N directed at an angle of 55o above the horizontal. Find (a) the work he does, (b) the force of friction, and (c) the coefficient of kinetic friction between the bag and the floor.

A boy throws a 140 g ball at a speed of 45 m/s and an initial angle of 30.0o.What is the kinetic energy of the ball at the highest point of its path?

A 6.0 g bullet moving at 500 m/s penetrates a sturdy wooden block to a depth of 3.00 cm. (a) Use work and energy considerations to find the average frictional force that stops the bullet. (b) Determine the time between the moment the bullet enters the block and the moment it stops moving.

A 0.70 kg object has a speed of 3.0 m/s at point P and kinetic energy of 8.0 J at point Q. What is (a) its kinetic energy at P? (b) its speed at point Q? (c) the total work done on the object as it moves from point P to Q?

work-13

A 2.3 g bullet leaves the barrel of a gun at a speed of 350 m/s. Find (a) its kinetic energy as it leaves the barrel. (b) the average force exerted on the bullet during its travel through the barrel. Assume that the length of the barrel is 55 cm.

A 15 kg crate is pulled up a rough incline with a force of 150 N applied parallel to the incline, which makes an angle of 30^o with the horizontal. Initial speed of the crate is 2.0 m/s. If the coefficient of kinetic friction is 0.47 and the crate is pulled a distance of 6.0 m, (a) how much work is done by the gravitational force? (b) How much work is done by the frictional force (c) what is the work done by the 150 N force and (d) What is the change in kinetic energy of the crate?

Create a data table of the planets in our solar system, period ratio*, age, period and semi major axis. Create a graph of Orbital Period Squared vs. Semi Major Axis Cubed. You may use logarithmic scale on your x and y axes to clearly distinguish the relationship between these two variables.

* period ratio is the ratio of the period of the planet and the period of the earth.

Use NASA’s official site to obtain these data.