A skier traveling 14.0 m/s reaches the foot of a steady upward
20.0o incline and glides...
A skier traveling 14.0 m/s reaches the foot of a steady upward
20.0o incline and glides 11.5 m up along this slope
before coming to rest. Using mechanical energy methods what is the
coefficient of friction?
5: A skier, m = 65 kg, glides on a perfect hill, 10 m high, no
friction. However, at the bottom is a spring, k = 1500 N/m , system
to stop the skier. A silly technique I will grant you. The spring
is not perfect, it loses 800 J of energy every time the spring
fully compresses or extends. Now we will have to assume the spring
never extends past its equilibrium position. A: What is the speed
of...
An object is thrown upward with an initial velocity of 32.1 m/s.
When the object reaches it maximum height, it is true of the
acceleration, a, and the velocity, v, that:
both its acceleration and velocity are zero
both its acceleration and velocity change sign
velocity is equal to zero, but acceleration is not
acceleration is equal to zero, but velocity is not
None of the above.
Please help. Only one answer is true. Please give reason
why.
A rocket is fired vertically upward. At the instant it reaches
an altitude of 1450 m and a speed of 265 m/s, it explodes into
three equal fragments. One fragment continues to move upward with a
speed of 292 m/s following the explosion. The second fragment has a
speed of 396 m/s and is moving east right after the explosion. What
is the magnitude of the velocity of the third fragment? Answer in
units of m/s
The acceleration of a rocket traveling upward is given by a = (8
+ 0.02s) m/s2, where s is in meters.(Figure 1). Initially, v = 0
and s = 0 when t = 0.
Determine the time needed for the rocket to reach an altitude of
s = 100 m .
An elevator accelerates upward at 1 m/s2. When the elevator is
moving upward at 2 m/s, a bolt drops from the ceiling which is 2.5
m above the ?oor. Assume that the bolt does not experience air
resistance. Calculate how long it takes for the bolt to hit the
?oor, how far it travels, and how fast it is going when it hits the
?oor of the elevator. Solve this problem in two reference frames,
one ?xed with respect to...
An automobile is traveling on a long, straight highway at a
steady 75.0 m/h when the driver sees a wreck 170 m ahead. At that
instant, she applies the brakes (ignore reaction time). Between her
and the wreck are two different surfaces. First there is 140 m of
ice, where the deceleration is only 1.20 m/s^2 . From then on, it
is dry concrete, where the deceleration is a more normal 7.90 m/s^2
. What was the car’s speed just...
During a free dance program in figure skating, Victor (m=71 kg)
glides at 2.1 m/s to a stationary Shae-Lynn (52 kg) and hangs
on.
a) What is their final speed?
b) How long will the pair slide after the "collision"?
c) How far will the pair slide after the "collision" if
coefficient of kinetic friction µk between their skates and the ice
is 0.052?
An ambulance is traveling south at 50 m/s, away from a car that
is traveling north at 30 m/s. The ambulance driver hears his siren
at a frequency of 750 Hz. The velocity of sound is 343 m/s .
What frequency (in Hz) does the driver of the car hear the
siren?
A car accelerates uniformly from rest and reaches a speed of
22.0 m/s in 9.00 s. If the diameter of the tire is 58.0 cm, find
(a) the number of revolutions the tire makes during the motion,
assuming that no slipping occurs. (b) What is the final angular
speed of a tire in revolutions per
second?
Answer: (54.3 rev, 12.1 rev/s) --> please show me
how to get this answer!
A car accelerates uniformly from rest and reaches a speed of
23.0 m/s in 8.96 s. Assume the diameter of a tire is 57.9 cm.
(a) Find the number of revolutions the tire makes during this
motion, assuming that no slipping occurs.
(b) What is the final angular speed of a tire in revolutions per
second?
rev/s