A boy throws a steel ball straight up. Consider the motion of the ball only after it has left the boy's hand but before it touches the ground, and assume that forces exerted by the air are negligible. For these conditions, the force(s) acting on the ball is (are):

A toy boat is being pushed with a force of 40.0 N [W] by its engines in a pond. A strong wind blows from the north, which exerts a force of 30.0 N on the boat. What is the net force acting on the ferry?   Question 1 options: a 50.0 N [W 36.9° S] b 70.0 N [W 53.1° S] c 50.0 N [W 53.1° S] d 70.0 N [W 36.9° S]

A freight train consists of two 8.00×104 kg5.60×104 kg engines and 45 cars with average masses of 5.50×104 kg5.50×104 kg. (a) What force must each engine exert backward on the track to accelerate the train at a rate of 4.00×10−2 m/s if the force of friction is 6.20×105 N, assuming the engines exert identical forces? This is not a large frictional force for such a massive system. Rolling friction for trains is small, and consequently trains are very energy-efficient transportation systems. (b) What is the force in the coupling between the 37th and 38th cars (this is the force each exerts on the other), assuming all cars have the same mass and that friction is evenly distributed among all of the cars and engines?

Newton's Third Law. A student in elementary physics finds himself in the middle of a large ice rink with a small but finite coefficient of friction between his feet and the ice. He has been taught Newton's Third Law. Since the law says that for every action there is an equal and opposite reaction, all forces add up to zero. Therefore he assumes that there will be no force possible to accelerate him toward the side of the rink and so he must stay at the center. (a) How do you tell him to get to the side?

An object has a mass of 15.3 kg and it has an initial velocity of 31.3 m/s (South) when it is acted upon by a force. The object's final velocity after the force has acted for a period of 5.20 s is 14.7 m/s (South). What is the force that acted on the object?

The high-speed winds around a tornado can drive projectiles into trees, building walls, and even metal traffic signs. In a laboratory simulation, a standard wood toothpick was shot by pneumatic gun into an oak branch. The toothpick mass was 0.15 g, its speed before entering the branch was 212 m/s, and its penetration depth was 17 mm. If its speed was decreased at a uniform rate, what was the magnitude of the force of the branch on the toothpick? Number Units

Boxes A and B are in contact on a horizontal, frictionless surface. Box A has mass 20.0 kg and box B has mass 5.0 kg. A horizontal force of 100 N is exerted on box B. What is the magnitude of the force that box B exerts on box A?