2) A 2kg mass in free space (no gravity) is seen moving with a constant acceleration of 4m/s^2 in the +j direction because of four forces, three of which are known and shown. Find the unknown force F_4 in unit vector notation

Suppose you are navigating a spacecraft far from other objects. The mass of the spacecraft is 4.0  104 kg (about 40 tons). The rocket engines are shut off, and you're coasting along with a constant velocity of ‹ 0, 30, 0 › km/s. As you pass the location ‹ 6, 9, 0 › km you briefly fire side thruster rockets, so that your spacecraft experiences a net force of ‹ 5.0  105, 0, 0 › N for 20 s. The ejected gases have a mass that is small compared to the mass of the spacecraft. You then continue coasting with the rocket engines turned off. Where are you an hour later? (Think about what approximations or simplifying assumptions you made in your analysis. Also think about the choice of system: what are the surroundings that exert external forces on your system?)f =         m

A train locomotive pulls a train with a mass of 1.10 ✕ 10^7kg on level rails. The locomotive exerts a constant force of 6.90 ✕ 10^5N on the train. How much time does it take to increase the speed of the train from rest to 64.0 km/h? (Ignore any resistance force from the rails on the wheels of the train. Enter your answer in minutes.)

As a protest against the umpire's calls, a baseball pitcher throws a ball straight up into the air at a speed of 22.0 m/s. In the process, he moves his hand through a distance of 1.20 m. If the ball has a mass of 0.150 kg, find the force he exerts on the ball to give it this upward speed.

A person in a kayak starts paddling, and it accelerates from 0 to 0.8 mile/hour in adistance of 0.8km. If the combined mass of the person and the kayak is 80kg, whatis the magnitude of the net force acting on the kayak?

A shot putter throws the 7.26-kg steel ball a horizontal distance of 14.7 m. The shot was released at a height of 2.71 m and the initial velocity made and angle of exactly 45 degrees with horizontal. a) What was the initial speed of the ball in m/s? v = b) If the ball moved 1.82 m (in a straight line) while it was being thrown, then what was the magnitude of the net force, in N, on the ball as it was being thrown? Fnet =

(a) Find the speed at which Superman (mass=90.0 kg) must fly into a train (mass = 17485 kg) traveling at 65.0 km/hr to stop it. Running into the train at that speed would severely damage both train and passengers. (b) Calculate the minimum time Superman must take to stop the train if the passengers experience an average horizontal force of 0.410 their own weight. (c) How far does the train then travel while being slowed to a stop?

Three forces acting on an object are given by F₁ = (−2.2î + 6.85ĵ) N, F₂ = (4.75î – 1.25ĵ) N, and F3 = (-401) N. The object experiences an acceleration of magnitude 3.80 m/s². (a) What is the direction of the acceleration? 98.50 X Note that the direction of the acceleration is the same as the direction of the net force.° (counterclockwise from the +x-axis) (b) What is the mass of the object? 9.964 kg (c) If the object is initially at rest, what is its speed after 11.0 s? 41.8 m/s (d) What are the velocity components of the object after 11.0 s? (Let the velocity be denoted by v.) ✓ = -41.34 m/s +6.18

A boat with mass of 7.4 * 10° kg is traveling at 6.1 * 10' m/s. What is the magnitude of the force required to stop the boat if it undergoes a displacement of 1.2 * 10' m? Express your answer in Newtons.

A skater of mass m = 60 kg is coasting along a smooth, level road with initial velocity v = given by: 3 m/s East. A sudden gust of wind exerts a time-varying force on him F(t) = ( 30 N) (1 – t) East | where t is measured in seconds. The gust of wind lasts from t = 0.0 to t = 2.0 seconds. What is the skater's speed at 2.0 seconds?