Problem 15
A car pulls a trailer down the highway. Let \(F_{\mathrm{t}}\) be the be the magnitude of the force on car due to the trailer. If the car and trailer are moving at a constant velocity across level ground, then \(F_{\mathrm{t}}=F_{c}\). If the car and trailer are accelerating up a hill, what is the relationship between the two forces?
Problem 17
If the forces that two interacting objects exert on each other are always exactly equal in magnitude and opposite in direction, how is it possible for an object to accelerate?
Problem 18
True or false: A physics book on a table will not move at all if and only if the net force is zero.
Problem 19
A mass slides on a ramp that is at an angle of \(\theta\) above the horizontal. The coefficient of friction between the mass and the ramp is \(\mu\). a) Find an expression for the magnitude and direction of the acceleration of the mass as it slides up the ramp. b) Repeat part (a) to find an expression for the magnitude and direction of the acceleration of the mass as it slides down the ramp.
Problem 23
The gravitational acceleration on the Moon is a sixth of that on Earth. The weight of an apple is \(1.00 \mathrm{~N}\) on Earth. a) What is the weight of the apple on the Moon? b) What is the mass of the apple?
Problem 24
A \(423.5-\mathrm{N}\) force accelerates a go-cart and its driver from \(10.4 \mathrm{~m} / \mathrm{s}\) to \(17.9 \mathrm{~m} / \mathrm{s}\) in \(5.00 \mathrm{~s}\). What is the mass of the go-cart plus driver?
Problem 25
4.25 You have just joined an exclusive health club, located on the top floor of a skyscraper. You reach the facility by using an express elevator. The elevator has a precision scale installed so that members can weigh themselves before and after their workouts. A member steps into the elevator and gets on the scale before the elevator doors close. The scale shows a weight of 183.7 lb. Then the elevator accelerates upward with an acceleration of \(2.43 \mathrm{~m} / \mathrm{s}^{2},\) while the member is still standing on the scale. What is the weight shown by the scale's display while the elevator is accelerating?
Problem 26
An elevator cabin has a mass of \(358.1 \mathrm{~kg},\) and the combined mass of the people inside the cabin is \(169.2 \mathrm{~kg} .\) The cabin is pulled upward by a cable, with a constant acceleration of \(4.11 \mathrm{~m} / \mathrm{s}^{2}\). What is the tension in the cable?
Problem 27
An elevator cabin has a mass of \(358.1 \mathrm{~kg}\), and the combined mass of the people inside the cabin is \(169.2 \mathrm{~kg} .\) The cabin is pulled upward by a cable, with a constant acceleration of \(4.11 \mathrm{~m} / \mathrm{s}^{2}\). What is the tension in the cable?
Problem 29
The density (mass per unit volume) of ice is \(917 \mathrm{~kg} / \mathrm{m}^{3}\) and the density of seawater is \(1024 \mathrm{~kg} / \mathrm{m}^{3}\). Only \(10.4 \%\) of the volume of an iceberg is above the water's surface. If the volume of a particular iceberg that is above water is \(4205.3 \mathrm{~m}^{3},\) what is the magnitude of the force that the seawater exerts on this iceberg?
