A 50-cm-diameter, 400 g beach ball is dropped with a 4.0 mg ant riding on the top. The ball experiences air resistance, but the ant does not. What is the magnitude of the normal force exerted on the ant when the ball’s speed is 2.0 m/s?
the normal force exerted on the ant is 3.07 N.
A 50-cm-diameter, 400 g beach ball is dropped with a 4.0 mg ant riding on the top. The ball experiences air resistance.
the ball’s speed is 2.0 m/s
diameter of the ball, D = 50 cm = 0.5m
radius of the ball, r = 0.25m
mass of the beach ball, m₁ = 400 g = 0.4 kg
mass of the ant, m₂ = 4 x 10⁻⁶ kg
speed of the ball, v = 2 m/s
The area of the ball, assuming spherical ball is given by;
A = 4πr²
A = 4π(0.25)² = 0.7854 m²
The drag force (resistance) experienced by the spherical ball is given as;
C is the drag coefficient of the spherical ball = 0.45
ρ is density of air = 1.21 kg/m³
The downward force of the ball due to its weight and that of the ant is given by;
The net downward force experienced by the ball is given by;
This downward force experienced by the ball is equal to the normal reaction it exerts on the ant.
Thus, the normal force exerted on the ant is 3.07 N.
The coefficient of static friction is between the two blocks in FIGURE . The coefficient of kinetic friction between the lower block and the floor is . Forcecauses both blocks to cross a distance of , starting from rest. What is the least amount of time in which this motion can be completed without the top block sliding on the lower block?
Problems 51 and 52 show the free-body diagrams of two interacting systems. For each of these, you are to
a. Write a realistic problem for which these are the correct freebody diagrams. Be sure that the answer your problem requests is consistent with the diagrams shown.
b. Finish the solution of the problem.
While driving to work last year, I was holding my coffee mug in my left hand while changing the CD with my right hand. Then the cell phone rang, so I placed the mug on the flat part of my dashboard. Then, believe it or not, a deer ran out of the woods and on to the road right in front of me. Fortunately, my reaction time was zero, and I was able to stop from a speed of in a mere , just barely avoiding the deer. Later tests revealed that the static and kinetic coefficients of friction of the coffee mug on the dash are and , respectively; the coffee and mug had a mass of ; and the mass of the deer was Did my coffee mug slide?
94% of StudySmarter users get better grades.Sign up for free