Just after opening a parachute of negligible mass, a parachutist of mass 90.0 kg experiences an instanta- neous upward acceleration of 1.00 m/s2. Find the force of the air on the parachute.

Consider two blocks connected by a string (call this the internal string) and being pulled vertically upward by another string (the external string) attached to block A. Suppose that blocks A and B have masses of 3.0 kg and 2.0 kg, respectively, and suppose that the external string’s tension has a magnitude of 55 N. The internal string’s mass is 100 g. Find the acceleration of the system, the magnitude of the tension force on block B, and the difference in the magnitudes of the tension forces exerted by each end of the string.    The acceleration of the system is ______ m/s2.   The tension force on block B is ____ N.   The difference in the magnitudes of the tension forces exerted by each end of the string is ______ N.

A 78.0 kg man stands on a spring scale in an elevator. Starting from rest, the elevator ascends, attaining its maximum speed of 1.83 m/s in 0.800 s. It travels with this constant speed for the next 5.00 s. The elevator then undergoes a uniform acceleration in the negative y direction for 1.70 s and comes to rest. (a) What does the spring scale register before the elevator starts to move? (b) What does it register during the first 0.800 s? N (c) What does it register while the elevator is traveling at constant speed? N (d) What does it register during the time it is slowing down? N

A man enters an elevator holding two boxes - one on top of the other. The top box has a mass of 6.0 kg and the bottom box has a mass of 8.0 kg. The man sets the two boxes on a metric scale sitting on the floor. When accelerating upward from rest, the man observes that the scale reads a value of 166 N; this is the upward force upon the bottom box. Determine the acceleration of the elevator (and boxes) and determine the forces acting between the boxes.

A 120-kg astronaut is riding in a rocket sled that is sliding along an inclined plane. The sled has a horizontal component of acceleration of 5.0 m/s2 and a downward component of 3.8 m/s2 . Calculate the magnitude of the force on the rider by the sled. (Hint: Remember that gravitational acceleration must be considered.)

A sled of mass 95 kg is being pushed up a slope with an applied force of 937 N. The slope is inclined with an angle of 43 degrees with respect to the horizontal. The coefficient of friction between the sled and the hill is 0.26. Find the acceleration of the crate (in m/s2).

A sailboat with a mass of 2.1 x 10^3 kg experiences an ocean current force of 3.45 x 10^3 directed to the east and a wind force against its sails with a magnitude of 6.53 x 10^3 directed toward the northwest (45.0^ N of W)What is the magnitude of the resultant acceleration of the boat?

Two blocks, each of mass 1.61 kg, hang from the ceiling of an elevator which accelerates upward with an acceleration of 1.50 m/s2. Find the tension, T2, in N.

A train pulls away from a station with a constant acceleration of 5.00 m/s2, after starting at rest. A ball of mass 3.20 kg hangs from a string attached to the ceiling of the train carriage. (1) Draw a sketch showing all the forces on the ball, indicating the direction of the acceleration vector. (2) Compute the angle that the string makes with the vertical.

You have a tray of mass 100 grams which is loaded with an additional 200 grams. It is attached via a string to a falling mass. The cart accelerates at 1.00 m/s2 for a time of 0.75 s. What is the magnitude of the force of tension (in N)?