8. You want to move a 500-N crate across a level floor. To start the crate moving, you have to pull with a 230 N horizontal force. Once the crate "break loose" and starts to move, you can keep it moving at constant velocity with only 200 N. What are the coefficients of static and kinetic friction? 9. A small car with mass 0.800 kg travels at constant speed on the inside of a track that is a vertical circle with radius 5.00 m (Fig. E5.42). If the normal force exerted by the track on the car when it is at the top of the track (point B) is 6.00 N, what is the normal force on the car when it is at the bottom of the track (point A)? v-12.0 m/s 5.00 m 12.0 m/s
8. You want to move a 500-N crate across a level floor. To start the crate moving, you have to pull with a 230 N horizontal force. Once the crate "break loose" and starts to move, you can keep it moving at constant velocity with only 200 N. What are the coefficients of static and kinetic friction? 9. A small car with mass 0.800 kg travels at constant speed on the inside of a track that is a vertical circle with radius 5.00 m (Fig. E5.42). If the normal force exerted by the track on the car when it is at the top of the track (point B) is 6.00 N, what is the normal force on the car when it is at the bottom of the track (point A)? v-12.0 m/s 5.00 m 12.0 m/s
Related questions
Question
IMPORTANT NOTE: ANSWER ITEMS 8 AND 9 ONLY
Transcribed Image Text:1. A dog running in an open field has components of velocity v, 2.6 m/s and v/ -2.8 m/satt, 10.0s. For
the time interval from t 10.0s to ta-20.0 s the average acceleration of the dog has magnitude 0.45 m/s²
and direction 31.0° measured from the +x-axis toward the +y-axis. At t-20.0 s,
what are the x- and y-components of the dog's velocity?
a.
b. What are the magnitude and direction of the dog's velocity?
c.
Sketch the velocity vectors at and How do these two vectors differ?
2. A man stands on the roof of a 15.0-m-tall building and throws a rock with a velocity of magnitude 30.0 m/s
at an angle of 33.0° above the horizontal. You can ignore air resistance. Calculate (a) the maximum height
above the roof reached by the rock; (b) the magnitude of the velocity of the
rock just before it strikes the ground; and (c) the horizontal range from the
base of the building to the point where the rock strikes the ground.
3. A Ferris wheel with radius 14.0 m is tuming about a horizontal axis through
its center (refer to figure). The linear speed of a passenger on the rim is
constant and equal to 7.00 m/s. What are the magnitude and direction of the
passenger's acceleration as she passes through (a) the lowest point in her
circular motion? (b) The highest point in her circular motion? (c) How much
time does it take the Ferris wheel to make one revolution?
4. Workmen are trying to free an SUV stuck in the mud. To extricate the vehicle,
they use three horizontal ropes, producing the force vectors shown in the figure. (a)
Find the x- and y-components of each of the three pulls. (b) Use the components to
find the magnitude and direction of the resultant of the three pulls.
5.
Two 25.0-N weights are suspended at opposite ends of a rope that passes over a
light, frictionless pulley. The pulley is attached to a chain that goes to the ceiling. (a)
What is the tension in the rope? (b) What is the tension in the chain?
6. On September 8, 2004, the Genesis spacecraft crashed in the Utah desert
because its parachute did not open. The 210-kg capsule hit the ground at 311 km/h
and penetrated the soil to a depth of 81.0 cm. (a) Assuming it to be constant, what was its acceleration (in
m/s² and in g's) during the crash? (b) What force did the ground exert on the capsule during the crash?
Express the force in newtons and as a multiple of the capsule's weight. (c) For how long did this force last?
7. A stonemason drags a marble block across a floor by pulling on a rope attached to the block. The block is
not necessarily in equilibrium. How are the various forces related? What are the action-reaction pair?
You want to move a 500-N crate across a level floor. To start the crate moving, you have to pull with a 230
N horizontal force. Once the crate "break loose" and starts to move, you can keep it moving at constant
velocity with only 200 N. What are the coefficients of static and kinetic
friction?
8.
788 N
53°
32
411 N
985 N
9. A small car with mass 0.800 kg travels at constant speed on the inside of a
track that is a vertical circle with radius 5.00 m (Fig. E5.42). If the normal
force exerted by the track on the car when it is at the top of the track (point
B) is 6.00 N, what is the normal force on the car when it is at the bottom of
the track (point A)?
v = 12.0 m/s
5.00 m
12.0 m/s
A
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 3 steps with 2 images
