A man holding a rock sits on a sled that is sliding across a frozen lake (negligible friction) with a speed of 0.490 m/s. The total mass of the sled, man, and rock is 94.0 kg. The mass of the rock is 0.270 kg and the man can throw it with a speed of 15.5 m/s. Both speeds are relative to the ground. Determine the speed of the sled (in m/s) if the man throws the rock forward (i.e., in the direction the sled is moving). m/s Determine the speed of the sled (in m/s) if the man throws the rock directly backward. m/s

An object has a velocity (4.04 m/s)i + (-4.96 m/s)j + (4.44 m/s)k. In a time of 3.84 s its velocity becomes (-3.75 m/s)i + (0.00 m/s)j + (4.44 m/s)k. If the mass of the object is 2.97 kg, what is the magnitude of the net force on the object, in N, during the 3.84 s? Assume the acceleration is constant.

Two horizontal forces, P and Q, are acting on a block that is placed on a table. We know that P is directed to the left but the direction of Q is unknown; it could either be directed to the right or to the left. The object moves along the x-axis. Assume there is no friction between the object and the table. Here P = -6.1 N and the mass of the block is 3.8 kg. P (a) What is the magnitudeand direction of Q (in N) when the block moves with constant velocity? (Indicate the direction with the sign of your answer.) 6.1 N (b) What is the magnitude and direction of Q (in N) when the acceleration of the block is +7.5 m/s2. (Indicate the direction with the sign of your answer.) X 22.4 The acceleration given here is due to the net force acting on the object. N (c) Find the magnitude and direction of Q (in N) when the acceleration of the block is -7.5 m/s2. (Indicate the direction with the sign of your answer.) X -34.6 What is the direction of motion of the object when the acceleration is…

The acceleration of a particle moving along the = -7 t + 4 t* + 3 t2, 7. x-axis is given by the function where a is in meters per second squared and t in seconds. What is the particle's velocity at t = 2 s if the object's mass is 11.3 kg and has an initial velocity of 1.6 m/s?

Mary applies a force of 78 N to push a box with an acceleration of 0.49 m/s2. When she increases the pushing force to 86 N, the box's acceleration changes to 0.73 m/s2. There is a constant friction force present between the floor and the box. (a) What is the mass of the box in kilograms?  kg (b) What is the coefficient of kinetic friction between the floor and the box?

A lump of clay of mass 0.21 kg is dropped from a height of 5.5 m. The clay comes to a full stop 0.071 s after the moment it first touched the ground. What is the magnitude in newtons of the average force of impact that the clay experienced? Express your answer in two decimal places, with units of Newtons.

In a performance test, each of two cars takes 8.6 s to accelerate from rest to 26 m/s. Car A has a mass of 1357 kg, and car B has a mass of 1950 kg. Find the net average force that acts on (a) car A and (b) car B during the test. (a) (b)

A 1.90 kg box is moving to the right with speed 9.00 m/s on a horizontal, frictionless surface. At t = 0 a horizontal force is applied to the box. The force is directed to the left and has magnitude F(t)=( 6.00 N/s^2 )t2 If the force continues to be applied, what is the velocity of the box at 3.50 s?

A hockey puck with mass 0.225 kg is at rest at the origin (x = 0) on the horizontal, frictionless surface of an ice rink. At time t = 0 a player applies a force of 9.50 N on the puck, parallel to the positive x- axis. She continues to apply this force until t = 0.850s. What are the position and speed of the puck at t = 0.850 s?

The muzzle velocity of a typical 500 g spud is 25 m/s . The force given by the spud is K/(x+.09) where x is the distance of the barrel in meters. If the length of the barrel is 75 cm, what is the constant K? What is the force on the spud?