An object of mass 0.77 kg is initially at rest. When a force acts on it for 2.9 ms it acquires a speed of 12.7 m/s. Find the magnitude (in N) of the average force acting on the object during the 2.9 ms time interval. (Enter a number.) N

A car moving at 30 m/s crashes into a tree and stops in 0.3 s. Calculate the force the seat belt exerts on a passenger in the car to bring him to a halt. The mass of the passenger is 84 kg. (Enter the magnitude.) N

A rocket takes off from Earth's surface, accelerating straight up at 45.2m/s2. Calculate the normal force (in N) acting on an astronaut of mass 85.9kg, including his space suit. (Assume the rocket's initial motion parallel to the +y-direction. Indicate the direction with the sign of your answer.) N

A bullet is accelerated down the barrel of a gun by hot gases produced in the combustion of gun powder. What is the average force (in N) exerted on a 0.0500 kg bullet to accelerate it to a speed of 500 m/s in a time of 1.90 ms (milliseconds)? (Enter the magnitude.) N

A massless spring with spring constant 26 N/m hangs vertically. A body of mass 1.0 kg is attached to its free end and then released. Assume that the spring was unstretched before the body was released. Find how far below the initial position the body descends. I don't understand why I'm getting this first part wrong specifically because the formula is just x= mg/k because F=kx.

Please answer and solve the question correctly. Thank you!

After falling from rest from a height of 29 m, a 0.45-kg ball rebounds upward, reaching a height of 19 m. If the contact between ball and ground lasted 2.2 ms, what average force was exerted on the ball? (Enter the magnitude.) N

A physics professor is pushed up a ramp inclined upward at an angle 30.0° above the horizontal as he sits in his desk chair that slides on frictionless rollers. Part A The combined mass of the professor and chair is 86.0 kg. He is pushed a distance 2.10 m along the incline by a group of students who together exert a constant horizontal force of 610N. The professor's speed at the bottom of the ramp is 1.85 m/s Use the work-energy theorem to find his speed at the top of the ramp. Express your answer in meters per second. V ΑΣφ ? V = m/s 國

k A 13.00 kg particle starts from the origin at time zero. Its velocity as a function of time is given by = 10t² + 1tj where is in meters per second and t is in seconds. (Use the following as necessary: t.) V (a) Find its position as a function of time. ŕ= esc 10/³1 + ²/2 2²; 3 (b) Describe its motion qualitatively. The particle starts from rest at the origin, starts moving in the y direction, and gains speed faster and faster while turning to move more and more nearly parallel to the x axis. Score: 0.06 out of 0.06 Comment: (c) Find its acceleration as a function of time. a = 20ti + lj m/s² (d) Find the net force exerted on the particle as a function of time. F= T= (e) Find the net torque about the origin exerted on the particle as a function of time. N m X X (f) Find the angular momentum of the particle as a function of time. Ľ Need Help? Read It F1 N x (g) Find the kinetic energy of the particle as a function of time. K= x kg m²/s X (h) Find the power injected into the particle as a…

You are applying a constant horizontal force F⃗ =(−7.60N)ι^+(3.00N)j^F→=(−7.60N)ι^+(3.00N)j^ to a crate that is sliding on a factory floor.     Part A At the instant that the velocity of the crate is v⃗ =(3.70m/s)ι^+(2.20m/s)j^v→=(3.70m/s)ι^+(2.20m/s)j^, what is the instantaneous power supplied by this force? Express your answer with the appropriate units.