Homework Statement
the largest of the Great Lakes, Lake Superior contains 1.2*10^16kg of fresh water, which has a specific capacity of 4186J/kg*C and a latent heat of fusion of 3.33*10^5J/kg.
a.) If Lake Superior were still liquid at 0C, how much energy would need to be removed from the lake...
Homework Statement
An 9 g bullet is fired into a 2.5 kg pendulum bob which is initially at rest and becomes embedded in the bob. The pendulum then rises a vertical distance of 6cm.
What was the initial speed of the bullet? What will be the kinetic energy of the pendulum when the pendulum...
Homework Statement
a 50 kg diver steps off a diving board and drops straight down into the water. The water provides an upward average net force of 1500 N. If the diver comes to rest 5.0m below the water's surface, what is the total distance between the diving board and the diver's stopping...
Homework Statement
a 2.1*10^3 kg car starts from rest at the top of a driveway that is sloped at an angle of 20 with the horizontal. An average friction force of 4.0*10^3 N impedes the car's motion so that the car's speed at the bottom of the driveway is 3.8m/s., What is the length of the...
Homework Statement
a student wearing a frictionless in-line skates on a horizontal surface is pushed by a friend with a constant force of 45N. How far must the student be pushed, starting from rest, so that her final kinetic energy is 352J?
Homework Equations
The Attempt at a...
Homework Statement
a 3 kg ball is dropped from rest from the roof on a building 176.4 m high. While the ball is falling, a horizontal wind exerts a constant force of 12 N on the ball?
Part 1) How long does the ball take to hit the ground?
Part 2) How far from the building does the ball hit the...
Homework Statement
a 5.1*10^2 kg bundle of bricks is pulled up a ramp at an incline of 14 degrees to a construction site. the force needed to move the bricks up the ramp is 4.1*10^3 N. What is the coefficient of static fiction between the bricks and the ramp?
Homework Equations
well...
Homework Statement
use to answer 1 and 2. A truck driver slams on the brakes and skids to a stop through a displacement of x.
1.) if the truck's mass doubles, find the truck's skidding distance in terms of x.(hint:increasing the mass increases the normal force.)
a. x/4
b. x
c. 2x
d. 4x...
Homework Statement
a.) a box slides down a 30 degree ramp with an acceleration of 1.20 m/s^2. Determine the kinetic friction between the box and the ramp.
Homework Equations
The Attempt at a Solution
the equation is uk=Fk/Fn but they did not provide me with atleast one force or...
Homework Statement
http://img150.imageshack.us/my.php?image=toottzx0.png
Homework Equations
I have the picture and everything but i just need help with the angles. Like i am a bit confused about how to draw the angles and stuff please help.
The Attempt at a Solution
Homework Statement
which of the following is a coordinate system for specifying the precise location of objects in space?
a. frame of reference
b. diagram
c. x-axis
d. y-axis
Homework Equations
The Attempt at a Solution
I thought it would be a diagram since it would use vectors...
Homework Statement
how can you find the initial velocity if the angle, horizontal distance and the vertical distance is given?
Homework Equations
The Attempt at a Solution
every equation i use gives me a different answer so i have no clue which one is correct
Homework Statement
salmon often jump waterfalls to reach their breeding grounds. One salmon starts 2m from a waterfall that is .55m tall and jumps at an angle of 32degrees. what must be the salmon's minimum speed to reach the waterfall?
Homework Equations
The Attempt at a Solution...
Homework Statement
a baseball is thrown at an angle of 25 degrees relative to the ground at a speed of 23.0m/s. If the ball was caught 42 m from the thrower, how long was it in the air? how high did the ball travel before being caught?
Homework Equations
The Attempt at a Solution...
Homework Statement
You are a pilot on an aircraft carrier. You must fly to another aircraft carrier, now 1450 km at 45 degree of your position, moving at 56 km/hr due east. The wind is blowing from the south at 72 km/hr. Calculate the heading and airspeed needed to reach the carrier 2.5 hour...
Homework Statement
two students are standing on a fire escape, one twice as high as the other. simultaneously, each drops a ball. if the first ball strikes the ground at time t1 when willt he second ball strike the ground?
A)t2=4t1
B)t2=5/4t1
C)t2=2t1
D)t2=squareroot of 2 times t1...
Homework Statement
a kitten pushes a ball of yarn rolling toward it at 1.00 cm/s with its nose, displacing the ball of yarn 17.5 cm in the opposite direction in 2.00 s. What is the acceleration of the ball of yarn?
Homework Equations
The Attempt at a Solution
i used...
Homework Statement
ball is thrown upward from the ground with an initial speed of 25m/s; at the same instant a ball is dropped from rest from a building 15m high. After how long will the balls be at the same height?
Homework Equations
The Attempt at a Solution
well the first ball...
in a race, a tortoise runs at 10cm/s and hare runs at 200cm/s. both start at the same time, but the hare stops to rest for 2.00 min. The tortoise wins by 20.0cm.
Part 1) At what time does the tortoise finish the line?
Part 2) What is the length of the race?
I would really appreciate it if you...