Using the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time, we can calculate the character's velocity after 2 seconds: v = 5 m/s + (-9.8 m/s^2) * 2 s = -19.6 m/s.

Since the ball is thrown horizontally, its vertical velocity is 0 m/s. Using the equation s = ut + 0.5*a*t^2, where s is the distance traveled, u is the initial velocity, a is the acceleration due to gravity (-9.8 m/s^2), and t is the time, we can calculate the horizontal distance traveled by the ball: s = 10 m/s * t + 0.5*(-9.8 m/s^2)*t^2. Solving for t when s = 50 meters, we get t = 2 seconds. Substituting t back into the equation, we find that the ball travels 20 meters horizontally before hitting the ground.

Since the car is moving at a constant speed, the net force acting on it is 0 N. This is because the forces acting on the car, such as friction and air resistance, are balanced out by the force applied by the engine.

The period of a pendulum is given by the equation T = 2π√(L/g), where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity. Solving for g, we get g = 4π^2L/T^2. Substituting the given values, we find that g = 9.8 m/s^2.

The force acting on the rocket at the moment of launch is equal to the mass of the rocket multiplied by the acceleration due to gravity (9.8 m/s^2). Since the rocket is moving vertically, the acceleration due to gravity is acting in the opposite direction of the rocket's motion. Therefore, the force acting on the rocket is 1000 kg * 9.8 m/s^2 = 1000 N.

The maximum height reached by the ball is equal to the initial velocity squared divided by twice the acceleration due to gravity. In this case, the maximum height is (10 m/s)^2 / (2 * 9.8 m/s^2) = 10 meters.

The force of friction acting on the car is equal to the coefficient of friction multiplied by the normal force. Since the car is moving at a constant speed, the normal force is equal to the weight of the car, which is 2000 kg * 9.8 m/s^2 = 19600 N. Assuming a coefficient of friction of 0.3, the force of friction is 0.3 * 19600 N = 5880 N.

The force exerted by a spring is equal to the spring constant multiplied by the displacement from the equilibrium position. In this case, the force exerted by the spring is 100 N/m * 0.1 m = 10 N.

The period of a pendulum is given by the equation T = 2π√(L/g), where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity. Solving for L, we get L = (T^2 * g) / (4π^2). Substituting the given values, we find that L = (4 s)^2 * 9.8 m/s^2 / (4π^2) = 1 meter.

The force acting on the rocket at the moment of launch is equal to the mass of the rocket multiplied by the acceleration due to gravity (9.8 m/s^2). Since the rocket is moving vertically, the acceleration due to gravity is acting in the opposite direction of the rocket's motion. Therefore, the force acting on the rocket is 2000 kg * 9.8 m/s^2 = 2000 N.

Since the ball is thrown horizontally, its vertical velocity is 0 m/s. Using the equation s = ut + 0.5*a*t^2, where s is the distance traveled, u is the initial velocity, a is the acceleration due to gravity (-9.8 m/s^2), and t is the time, we can calculate the horizontal distance traveled by the ball: s = 15 m/s * t + 0.5*(-9.8 m/s^2)*t^2. Solving for t when s = 20 meters, we get t = 2 seconds. Substituting t back into the equation, we find that the ball travels 30 meters horizontally before hitting the ground.

The force of friction acting on the car is equal to the coefficient of friction multiplied by the normal force. Since the car is moving at a constant speed, the normal force is equal to the weight of the car, which is 3000 kg * 9.8 m/s^2 = 29400 N. Assuming a coefficient of friction of 0.25, the force of friction is 0.25 * 29400 N = 7350 N.

The force exerted by a spring is equal to the spring constant multiplied by the displacement from the equilibrium position. In this case, the force exerted by the spring is 200 N/m * 0.2 m = 40 N.

The period of a pendulum is given by the equation T = 2π√(L/g), where T is the period, L is the length of the pendulum, and g is the acceleration due to gravity. Solving for L, we get L = (T^2 * g) / (4π^2). Substituting the given values, we find that L = (6 s)^2 * 9.8 m/s^2 / (4π^2) = 2 meters.

The force acting on the rocket at the moment of launch is equal to the mass of the rocket multiplied by the acceleration due to gravity (9.8 m/s^2). Since the rocket is moving vertically, the acceleration due to gravity is acting in the opposite direction of the rocket's motion. Therefore, the force acting on the rocket is 3000 kg * 9.8 m/s^2 = 3000 N.