Exam 5: Applying Newtons Laws

A pickup truck is moving at 25 m/s with a toolbox of mass m resting on the bed of the truck 2.5 m behind the cab.Suddenly the brakes are applied,causing the toolbox to slide,and the truck comes to a stop in 4.7 s.The coefficient of kinetic friction between the toolbox and the bed of the truck is 0.28.After the brakes are applied,how much time elapses before the toolbox strikes the cab?

An 80.0-kg object is falling and experiences a drag force due to air resistance.The magnitude of this drag force depends on its speed,v,and obeys the equation What is the terminal speed of this object?

A rope pulls on the lower block in the figure with a tension force of 20 N.The coefficient of kinetic friction between the lower block and the surface is 0.16.The coefficient of kinetic friction between the lower block and the upper block is also 0.16.The pulley has no appreciable mass or friction.What is the acceleration of the 2.0 kg block?

A traffic light weighing 100 N is supported by two ropes as shown in the figure.The tensions in the ropes are closest to

A 60.0-kg person rides in elevator while standing on a scale.The elevator is traveling downward but slowing down at a rate of 2.00 m/s².The reading on the scale is closest to

A car drives over a hilltop that has a radius of curvature 0.120 km at the top of the hill.At what speed would the car be traveling when it tires just barely lose contact with the road when the car is at the top of the hill?

Two objects are connected by a very light flexible string as shown in the figure,where and .You can ignore friction and the mass of the pulley. (a)Draw free-body diagrams for each object. (b)Calculate the magnitude of the acceleration of each object. (c)Calculate the tension in the string.

The figure shows two forces acting on an object,with magnitudes and What third force will cause the object to be in equilibrium (acceleration equals zero)?

The figure shows two packages that start sliding down a 20° ramp from rest a distance along the ramp from the bottom.Package A has a mass of 5.0 kg and a coefficient of kinetic friction 0.20 between it and the ramp.Package B has a mass of 10 kg and a coefficient of kinetic friction 0.15 between it and the ramp.How long does it take package A to reach the bottom?

The figure shows a 2000 kg cable car descending a high hill.A counterweight of mass on the other side of the hill aids the brakes in controlling the cable car's speed.The rolling friction of both the cable car and the counterweight are negligible.How much braking force does the cable car need to descend at constant speed?

A ball of mass 5.0 kg is suspended by two wires from a horizontal arm that is attached to a vertical shaft,as shown in the figure.The shaft is in uniform rotation about its axis.The rate of rotation is adjusted until the tensions in the two wires are EQUAL.At that speed,the radial acceleration of the ball is closest to

A 1000-kg car is slowly picking up speed as it goes around a horizontal curve whose radius is 100 m.The coefficient of static friction between the tires and the road is 0.350.At what speed will the car begin to skid sideways?

Two unequal masses M and m (M > m)are connected by a light cord passing over a pulley of negligible mass,as shown in the figure.When released,the system accelerates.Friction is negligible.Which figure below gives the correct free-body force diagrams for the two masses in the moving system?

A 1.20-kg ball is hanging from the end of a rope.The rope hangs at an angle 25.0° from the vertical when a 15.0 m/s horizontal wind is blowing.If the wind's force on the rope is negligible,what drag force does the wind exert on the ball?

A 250-kg crate is on a rough ramp,inclined at 30° above the horizontal.The coefficient of kinetic friction between the crate and ramp is 0.22.A horizontal force of 5000 N is applied to the crate,pushing it up the ramp.What is the acceleration of the crate?

Two bodies P and Q on a smooth horizontal surface are connected by a light cord.The mass of P is greater than that of Q.A horizontal force (of magnitude F) is applied to Q as shown in the figure, accelerating the bodies to the right. The magnitude of the force exerted by the connecting cord on body P will be

In a shuffleboard game,the puck slides a total of before coming to rest.If the coefficient of kinetic friction between the puck and the horizontal board is 0.28,what was the initial speed of the puck?

In the figure,a T-bar ski tow pulls a skier up a hill inclined at 10° above horizontal.The skier starts from rest and is pulled by a cable that exerts a tension T at an angle of 30° above the surface of the hill.The mass of the skier is 60 kg and the effective coefficient of kinetic friction between the skis and the snow is 0.100.What is the maximum tension in the cable if the starting acceleration is not to exceed 0.400 g?

A 200 g hockey puck is launched up a metal ramp that is inclined at a 30° angle.The coefficients of static and kinetic friction between the hockey puck and the metal ramp are and ,respectively.The puck's initial speed is 4.9 m/s.What speed does it have when it slides back down to its starting point?

Two objects having masses m₁ and m₂ are connected to each other as shown in the figure and are released from rest.There is no friction on the table surface or in the pulley.The masses of the pulley and the string connecting the objects are completely negligible.What must be true about the tension T in the string just after the objects are released?