Put me in Coach

What enables a spider monkey to easily vary its center of gravity?

The long heavy tail of a spider monkey.

What kind of root system would you expect a very broad tree to have?

A very broad root system.

Why do you tend to hold your free arm away from your body when carrying a heavy load with one arm?

To change the center of gravity of your body and the load.

What happens to the center of gravity of a table tennis ball you push beneath the surface of water?

rises

What component of the string tension provides the centripetal force for a rock swung in a conical pendulum?

The horizontal component of the string tension.

Where is the center of gravity of a softball bat located?

In the more massive end of the bat.

If Suzie Spacewalker is at relative rest beside a space station in Earth orbit, what can we conclude about her position?

She is also in Earth orbit.

What causes a person to fall over when trying to touch their toes while standing flat against a wall?

Their center of gravity is not located above their support area.

What is the direction of the force acting on clothes in the spin cycle of a washing machine?

Outward.

When will an object fall over?

If its center of gravity is not over its area of support.

What kind of equilibrium is a ball resting on the floor in?

Stable

What exerts the force on a ladybug resting on the bottom of a tin can being whirled horizontally?

The string.

In a future space habitat rotating about its long axis, what is the relative gravitational field along the axis?

Zero.

Who has greater angular speed on a merry-go-round, a horse near the outside rail or one near the inside rail?

Neither—they both have the same angular speed.

Why does a person weigh less at the equator than at the poles?

Due to the spin of the Earth.

What is the direction of the net force on a car traveling in a circle with constant speed?

Toward the center of the curve.

Why does a tin can whirled on the end of a string move in a circle?

There is an inward force acting on the can.

Which horse has greater linear speed on a merry-go-round, one near the outside rail or one near the inside rail?

The outside horse.

What path does the center of gravity of a spinning wrench follow on a frictionless tabletop?

A straight-line path with regular speed.

Where is the center of gravity located in a donut?

At a point where there is no mass.

What does an object thrown into the air with spin rotate around?

Its center of gravity.

If an object is in stable equilibrium, what happens to its center of gravity with any displacement?

It raises its center of gravity.

What centripetal force acts on a stunt motorcyclist riding on the inner vertical surface of a circular track?

The normal force.

What happens to the velocity of an object falling freely in a vacuum?

Its velocity increases.

How much does a freely falling object equipped with a speedometer increase its speed each second?

About 10 m/s.

What distance does a freely falling object fall each second?

A larger distance than in the second before.

What is the total time for a projectile fired straight up at 10 m/s to return to its starting point?

About 2 seconds.

What is the acceleration of a basketball player once their feet are off the floor when jumping?

Is g; no more, no less.

What does the speedometer in a moving car show?

The car's instantaneous speed.

What is one possible unit of speed?

All of the above (kilometers per hour, miles per hour, light years per century).

At the top of its path, what is the instantaneous speed of a ball thrown straight up?

0 m/s.

What speed will a freely falling object have after falling for 9 seconds?

About 90 m/s.

What happens to drops of water leaking from a faucet as they fall?

They get farther apart.

What is the average acceleration of a minivan that starts from rest and moves to 27 m/s in 9 seconds?

3 m/s².

If a feather and a coin are dropped at the same time in a tube filled with air, which reaches the bottom first?

The coin.

What is acceleration defined as?

The change in velocity divided by the time interval.

During the motion of a ball tossed vertically upward, what happens at its highest point?

The acceleration is always directed downward.

If a car travels 15 meters every second for three seconds, what is its acceleration?

0 m/s².

At the top of its path, what is the acceleration of a ball thrown straight up?

About 10 m/s².

When a ball is thrown upwards and caught when it comes down, how does its speed compare?

It is the same as the speed it had when thrown upwards.

What is true about a car going around a curve with a constant speed?

Its velocity is not constant.

What component of a projectile's velocity is independent of its vertical component?

The horizontal component.

Where does a projectile have minimum speed in its trajectory?

At the top of its path.

How far vertically will a cannonball fall after 3 seconds if launched horizontally at 100 m/s?

45 m.

What happens to an airplane flying into a headwind?

It loses ground speed.

What does a soccer ball kicked at an angle move horizontally in the next second?

15 m.

What happens to a rock thrown straight up after reaching the top of its path?

The same acceleration as when it was at the top of its path.

What is the escape velocity of a baseball thrown horizontally at 8 km/s without air drag?

It would escape Earth's atmosphere.

What is hang time in a vertical jump?

The time a jumper's feet are off the ground.

What is a scalar quantity?

A quantity that has magnitude.

How do you find the components of a vector?

All of the above (draw the vector, measure the sides, draw a rectangle so that it's the diagonal).

If a ball is thrown horizontally and an identical ball is dropped, which hits the ground first?

Neither—they both hit the ground at the same time.

What is true about a satellite in orbit?

It is simply a projectile.

What is the speed of a ball thrown straight upward at 10 m/s when it returns to the thrower's hand?

10 m/s.

If a cannonball is launched horizontally from a tower at 90 m/s, how far will it be after 1 second?

90 m downrange.

What would happen if an object is dropped and falls freely with an acceleration of g, but is then thrown upward at an angle?

Its acceleration would be g downward.

What is the resultant of a 15-unit vector and a 20-unit vector at right angles?

25 units.

What angle should an object be thrown at to go the farthest in the absence of air resistance?

45 degrees.

If a plane flies at 240 km/h against a 60 km/h tailwind, how fast does the plane's shadow move across the ground?

300 km/h.

How far will a ball thrown horizontally from a tall cliff fall in 1.0 second?

5 meters.

What initial speed must a ball be thrown to reach a pool 8.0 m away from a 5 m high building?

8 m/s.

What happens when an object reaches terminal velocity?

Its acceleration is 0 m/s².

What force is needed to equally accelerate a 16-kg brick with a push on a 4-kg brick?

With 4 times as much force.

If you pull horizontally on a desk with 150 N and it doesn't move, what is the friction force?

200 N.

What happens to a cart's acceleration if a load is dumped into it and its mass doubles?

It halves.

What happens to the velocity of a care package falling from a helicopter?

Its acceleration decreases.

What force is needed to accelerate a 4.0-kg physics book to 3.0 m/s²?

12.0 N.

What happens if the force on a cart doubles?

Its acceleration doubles.

What is the acceleration of a mass of 12 kg acted upon by a force of 12 N?

The same as for 6 kg with 6 N.

What is the acceleration of a 50-kg crate when pulled with 450 N and experiencing 250 N of friction?

4 m/s².

What is the net force on a 15-N object encountering 7 N of air resistance?

8 N.

Why do a tennis ball and solid steel ball accelerate at the same rate in the absence of air resistance?

The force acting on them is the same.

What does a constant force of 10 N against a particle result in if a second force of 10 N acts in the opposite direction?

The particle continues at the speed it had.

What is the net force on a 1 N apple in free fall?

1 N.

What is the net force on an 8 N falling object that encounters 8 N of air resistance?

0 N.

What does lying down and crawling on ice do to pressure?

It decreases pressure on the ice.

How much force is required to accelerate a car with a mass of 2500 kg at 3 m/s²?

7500 N.

What is torque defined as?

Force times lever arm.

What can increase your chance of loosening a nut with a wrench?

Extend the lever arm.

If a football is kicked through its center of gravity, what will it do?

Move without any tumbling or spinning.

Which has more rotational inertia: a bicycle wheel or a solid disk of the same mass?

The wheel.

When comparing a girl running with bent legs to straight legs, which has more rotational inertia?

With straight legs.

Which objects roll down an incline with greater acceleration?

Objects with small rotational inertia.

In the case of solid and hollow cylinders, which rolls down an incline faster?

Any solid cylinder.

Where is a person's rotational inertia least?

About the person's longitudinal axis.

What happens when a gymnast moves to a tucked position?

She decreases her rotational inertia.

What happens when an ice skater pulls in their hands?

Angular momentum must be conserved.

If one person leans toward the center of a seesaw, what happens to the other person?

They rise.

What is preferred for turning a stubborn screw?

A screwdriver with a wide handle.

What happens to your rotational speed on a Ferris Wheel halfway between the center and the rim compared to a regular Ferris Wheel?

It would be the same.

Which rolls down a hill sooner: a car tire alone or the same tire mounted on a rim?

The mounted tire.

Which object will reach the bottom of a hill first, a ring or a disk?

The disk.

What do oval-shaped cam pulleys provide at different orientations?

Different lever arm lengths.

At what mark should a 30.0-N weight be placed to balance a meter stick with a 10.0-N weight at the 15.0-cm mark?

61.7-cm mark.

If a 3-kg ball is whirled on a 2-m string at 4 m/s, how is its angular momentum expressed?

(24 kg)(m)(m/s).

Of a ring, a disk, and a solid ball, which reaches the bottom of a hill first?

The ball.

In physics, how is work defined?

Force times distance.

If two loads are lifted up one story, how much work is done?

Twice as much compared to lifting just one load.

How is power defined?

Work done divided by time taken.

What gives an object potential energy?

Its location.