A hare and a tortoise compete in a race over a straight course 1.10 km long. The tortoise crawls at a speed of 0.150 m/s toward the finish line. The hare runs at a speed of 7.15 m/s toward the finish line for 0.880 km and then stops to tease the slow-moving tortoise as the tortoise eventually passes by. The hare waits for a while after the tortoise passes and then runs toward the finish line again at 7.15 m/s. Both the hare and the tortoise cross the finish line at the exact same instant. Assume both animals, when moving, move steadily at their respective speeds.

(a) How far is the tortoise from the finish line when the hare resumes the race? m

(b) For how long in time was the hare stationary? s

Assume that the skier is 1.8 m tall and 0.30 m wide. Assume the skier's drag coefficient is 0.80.

What is the terminal speed for an 85 kg skier going down a 40 ∘ snow-covered slope on wooden skis μk= 0.060?

How to adaptation (response of rods and cones to changing light conditions) to a equivalent function in a camera

A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.490 m/s. The total mass of the sled, man, and rock is 95.0 kg. The mass of the rock is 0.260 kg and the man can throw it with a speed of 16.0 m/s. Both speeds are relative to the ground.

Determine the speed of the sled (in m/s) if the man throws the rock forward (i.e., in the direction the sled is moving).

_______m/s

Determine the speed of the sled (in m/s) if the man throws the rock directly backward.

_______m/s

d

Since the spokes of a bicycle wheel have much less mass than the rim, the wheel can be modeled as a cylindrical hoop of mass 1.90 kg and radius 0.6 m. This wheel rotates without friction about a vertical axis perpendicular to the disk and through its center. Standing on the rim is a kitten of mass 1.00 kg (the kitten can be modeled as a point mass). The wheel (with the kitten standing on it) rotates with an angular velocity of 0.600 revolutions per second.

a) What is the moment of inertia of the wheel/kitten system?

b) The kitten then scampers from its initial position inward on the wheel until it is standing at the center. What is the new moment of inertia of the wheel/kitten system?

c) What is the angular velocity of the system when the kitten reaches the center?

d) What is the ratio of the system

CALC- A web page designer creates an animation in which a dot on a computer screen has position r=[4 cm + (2.5cm/s^2)t^2] i +(5.0 cm/s)t j

a) find the magnitude and direction of the dot's average velocity between t=0 and t=2. b) Find the magnitude and direction of the instantaneous velocity at t=0, t=1, and t=2.

I understand how to solve for the magnitude for each of these questions but the answer in the back of the book for t=2 direction is 27 degrees. When using SOHCAHTOA, shouldn't it be tan^-1(10/5)? but the only way to get 27 is tan^-1(5/10)

Could someone explain to me why tanx(x/y) would be the case here?

A 0.0147-kg bullet is fired straight up at a falling wooden block that has a mass of 2.94 kg. The bullet has a speed of 760 m/s when it strikes the block. The block originally was dropped from rest from the top of a building and had been falling for a time t when the collision with the bullet occurs. As a result of the collision, the block (with the bullet in it) reverses direction, rises, and comes to a momentary halt at the top of the building. Find the time t.

Please give answer to 4 significant figures.

The figure below gives the speed v versus time t for a 0.490 kg object of radius 6.50 cm that rolls smoothly down a 30

A long, straight wire carries a current of 20.0 A, as shown in Figure 27-63. A rectangular coil that has two sides parallel to the straight wire has sides that are 5.00 cm long and 10.0 cm long. The side nearest to the wire is 2.00 cm from the wire. The coil carries a current of 5.00 A. (a) Find the force on each segment of the rectangular coil due to the current in the long, straight wire. What is the net force on the coil?

An object is located 1.5 m  from a 6.5-D lens. a) By how much does the image move if the object is moved 0.9 m closer to the lens? Follow the sign conventions. b) By how much does the image move if the object is moved 0.9 m farther from the lens? Follow the sign conventions.

An optical system consists of two thin lenses: +100. mm and -20.0 mm. They are separated by a distance of 50.0 mm. An object is placed 50.0 mm in front of the +100. mm lens. Determine:

a.   the final image location, and

b.   transverse magnification.

c.   Is the final image real or virtual? Why?

What makes other planetary systems different from one another, for example, the Earth is not the same as Venus or Mars? In the next couple of years, we will be sending people to Mars, evaluateand write about the challenges invovled in making this trip. Will human beings survive on Mars?

A line of charge is bent into a square with a side of 2 cm and a charge density of 3 microC/cm. Using Coulomb's law, determine the electric field at all points along the axis of the square (the line through the center of the square and perpendicular to it).

A uniform electric field with a magnitude of 6 × 10^6 N/C is applied to a cube of edge length 0.1 m as seen in Fig 22-2 above. If the direction of the E - field is along the +x-axis, what is the electric flux passing through the shaded face of the cube?

The pilot of an airplane executes a loop-the-loop maneuver in a vertical circle. The speed of the airplane is 305 mi/h, at the top of the loop and 450 mi/h at the bottom, and the radius of the circle is 1 180 ft. Note: His apparent weight is equal to the magnitude of the force exerted by the seat on his body. (a) What is the pilot's apparent weight at the lowest point if his true weight is 160 lb? (b) What is the magnitude of his apparent weight at the highest point?