A kite 75 ft above the ground moves horizontally at a rate of 12
ft/s. At...
A kite 75 ft above the ground moves horizontally at a rate of 12
ft/s. At what rate in ft/s is the angle between the string
(diagonal) and horizontal decreasing when 200 ft of string has been
let out?
A kite is stuck in a tree 40 ft above the ground
I am reeling in the string at a rate of 5 ft/min
a) how fast is my distance from the tree changing when i am 30
ft from the tree?
b) how fast is the angle of elevation changing at the same
time?
1. A student pulls horizontally on a 12 kg box, which then moves
horizontally with an acceleration of 0.2 m/s2. If the
student uses a force of 15 N, what is the coefficient of kinetic
friction of the floor?
2. A 30 kg block slides down a 20° ramp with an acceleration of
1.2 m/s2. What is the coefficient of kinetic friction
between the block and the ramp?
3. For a given velocity of projection in a projectile motion,
the...
From a point 96 ft above the ground, a stone is thrown
in such a way that it is at the same point: 3 sec after it was
thrown, as it was 2 sec after it was thrown. How long does it take
the stone to reach the ground?
A solid cylinder is mounted above the ground with its axis of
rotation oriented horizontally. A rope is wound around the cylinder
and its free end is attached to a block of mass 75.5 kg that rests
on a platform. The cylinder has a mass of 205 kg and a radius of
0.350 m. Assume that the cylinder can rotate about its axis without
any friction and the rope is of negligible mass. The platform is
suddenly removed from under...
An object is launched horizontally with a speed of 78.8 m/s. It
lands on the ground 19.6 m from where it was launched. How high
above the ground was it launched from? Report your answer in SI
units, rounded to two decimal places.
A 6.00-ft-tall man walks at 7.00 ft/s toward a street light
that is 15.0 ft above the ground. At what rate is the end of the
man's shadow moving when he is 10.0 ft from the base of the light?
Use the direction in which the distance from the street light
increases as the positive direction.
You launch a projectile horizontally from a building 29.5 m
above the ground at another building 40.6 m away from the first
building. The projectile strikes the second building 14.0 m above
the ground. What was the projectile s launch speed?
22.84 m/s
16.56 m/s
24.03 m/s
30.04 m/s
A 6.0-ft-tall girl stands on level ground. The sun is 23 ∘ above
the horizon.
How long is her shadow?
Express your answer using two significant figures.
b) A 5.0-m-wide swimming pool is filled to the top. The bottom
of the pool becomes completely shaded in the afternoon when the sun
is 25 ∘above the horizon.
How deep is the pool?
Express your answer using two significant figures.
A ball is thrown upward with an initial velocity of 32 ft/sec from a tower 48 feet above ground. Assume that the only force affecting the ball during travel is from gravity, which produces downward acceleration of 32 ft/sec^2. Then
The maximum height reached by the ball is: ____________________
The ball hits the ground at time t; _____________________
The distance s(in m) above the ground for a projectile fired
vertically upward with a velocity of 4(a) m/s as a function of time
t(in s) is given by s=4(a)t-4.(b)t2
a= 6 b=9
Find the answers to these questions
1. find t for v=0
2. find v for t=4
3. find v for t=5
what conclusions can you draw?