1. A net force of 2000N act on a rocket of mass 1000. kg. How long must the force be applied in order to increase the rockets velocity from 10.0 m/s to 200.0 m/s.
2. Marble A, mass 5.0 g, moves at a speed of 20.0cm/s. It collides with a second marble, B, mass 10.0 g, moving at 10.0cm/s in the same direction. After collision, marble A continues with a speed of 8.0 cm/s in th same direction. (a) calculate the marbles’ momenta before the collision 9b0 calculate the speed of marble B after the collision.
3. a 35.0 g bullet moving at 475 m/s strikes a 2.5 kg wooden block. the bullet pases through the block leaving at 275 m/s. if the block was originally at rest, with what veolicty is the block moving after the bullet leaves?
4. a 40.0 kg projectile leaves a 2000. kg launcher with a velocity of 800 m/s. what is the recoil velocity of the launcher?
5. upon launching, a model rocket expels 50.0 g of fuel from its exhaust at an average velocity of 600.0 m/s. if the rocket moves upward at 7.5 m/s what is teh mass of the rocket?
6. if a 2 kg object going 4m/s feels teh impulse indicated in the graph above, claculate its final velocity.
7.Blauc Hed carries a box up the stairs. How many times more work is required to carry the block up the stairs that are 3 times as high.? Explain.
8. if the box weighs 3 times as much then how much more work is required for Blauc to carry it up the stairs. Explain.
9 in orde to double the power of someone carrying the box up the stairs, their time must be…(answer)
10. Tommy runs up the stairs (4.6 m) carrying a box that is 55 kg in 3.5 sec. Timmy carries a box with the same mass but runs up the same set of stairs in 3 sec. (a) who did more work? explain (b) who is more powerful? explain.
11. Liki Fat Set pushes a 5 kg object with a force of 10 N along a frictionless surface a distance of 10 m in 3 sec. (A) write the conservation of energy equation (B) calculate your work done on the block. (C) calculate final velocity of the block. (D) calculate Liki’s power.

A 1.4 kg falling object (subject to the effects of aerodynamic drag) is 1800 m high, traveling at 34 m/s and has not yet reached terminal speed. It first reaches terminal speed at a height of 1340 m and the terminal speed is 37.3 m/s. a) Determine if the mechanical energy (
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E = K +Ug ) of the system consisting of the falling object and Earth’s gravity field has been conserved during the fall from 1800 m to 500 m. b) How much work (if any) including the correct sign (+ or -­‐) has been done on the system over this interval (presumably by the external drag force)? c) Will the energy of the system consisting of the object, the gravity field and the surrounding air be conserved over this interval? Explain your answer. Is there an additional energy that must be accounted for in this analysis? What is it and how much of it has been generated? Note: terminal speed is a constant speed.
48 kg diver jumps off a cliff (with a running start) into the ocean. The cliff is 50 m above the ocean below. Her coach, using a video of the dive, determines that at a point in flight when she has risen 0.7 m above the cliff, her speed1 (center of mass) is 0.5 m/s. Frictional effects such as drag are negligible. Formulate your solution using the diver and Earth’s gravity field as a system. Gravity does not do work on this system. It’s effects are captured in changes in potential energy. a) How much kinetic energy did she have at takeoff? What was her speed? b) How much kinetic energy will she have as she splashes into the ocean? c) What minimum amount of chemical energy needed to be consumed within the diver’s body in order for her to walk to the cliff, from ocean level, and then take off (jump)? Explain how you know.
1 Includes both x and y velocity components. This is not the highest point in the jump.

Problem 2:
Find the elevation h (km) where the weight of an object is one-tenth (1/10) its weight on the surface of the earth.me= 5.9742×1024 kg; re = 6,378 km
Problem 3:
Two identical asteroids travel through space side by side while touching each other. If the asteroids are composed of homogeneous pure iron ( = 7,874kg/m3) and are spherical, what diameter in meters and milesmust they have for their mutual gravitational attraction to be 5 N?