N e w t t o n ' ' s 2 n d
L a w s P r r o b l l e m s
1. The unbalanced force on a 2.0 x 10
3
kg satellite is 1.3 x 10
3
N from a small rocket. What is the acceleration of the satellite?
2. Joe pushes a 10.0 kg rock with a force of 11 N [E]. Jack pushes the rock with a force of 15 N [N]. There is no friction. What is the acceleration (magnitude and direction)?
3. A block, mass 10 kg and initially at rest is pushed by Pam with an applied force of 25 N [E]. After 3.0 seconds it is moving at 6.0 m/s [E]. Find the friction force and the coefficient of friction.
4. A farm worker is pulling a 95 kg crate of apple across the floor with a force of 350 N that is 15 o
above the horizontal. It is moving at a constant speed. a. What is the normal force on the crate? b. What is the force of friction on the crate? c. What are the net force and the acceleration of the crate?
1. A baseball hit by a bat with an average force of 1000 N accelerates at 4.0 x 10
3
m/s
2
. What is the balls mass?
2. What unbalanced force is needed to accelerate a 3.0 x 10
4
kg spacecraft at 2.5 m/s
2
?
3. How much applied force is needed to accelerate a 2.0 kg block of wood at 4.0 m/s
2
along a rough table, against a 10 N force of friction?
4. A jet plane pilot decides to accelerate horizontally. IF the thrust of the engines is increased to 50 000 N at a time when the air resistance acting on the 4000 kg plane is 30 000 N, what is the planes acceleration?
5. Matt's race car has a mass of 1200 kg and is able to accelerate from rest to a velocity of 30.0 m/s in only 5.0 s. Find the average acceleration and the necessary applied force if there is a constant friction force of 850 N opposing the motion.
6. A mass of 3.0 kg is falling through a viscous fluid, which provides an upward force of 15.0 N. a) What is the unbalanced force on the mass (draw a FBD) b) What is the acceleration of the mass?
7. A 2.0 kg ball is pushed from rest with an applied force of 6.0 N. The friction force is 2.0 N. How far has the ball rolled after 10.0 s?
8. A box, 5.0 kg, is pushed from rest for 55 m with an applied force of 22 N. If the coefficient of kinetic friction is 0.08, how long does it take to move the 55 m?
9. A 3.0 kg mass is being pushed east with an acceleration of 1.7 m/s
2
[E]. If the coefficient of friction is 0.50, find the applied force on the mass.
10. A 2.0 kg ball, falling freely experiences air friction of 11 N [UP]. What is its acceleration?
11. Mark is unlucky in a recent snowstorm and gets his car stuck in the snow. His friends remember their Physics lessons and attach ropes to his car to pull him out of the snow. Mike pulls with a force of 210 N [35 ° N of W]; Jeff pulls with a force of 180 N [W] and Shane pulls with a force of 175 N [22 ° S of W]. Use a scale diagram to draw and calculate the magnitude and direction of the resultant force vector acting on Mark's car.
12. A student is pushing a 100 kg trunk across the floor with an applied force of 250 N at and angle of 35 o
with the horizontal as pictured in the diagram. a. Draw a FBD for the situation. b. Determine the normal force on the trunk. c. If the coefficient of friction is 0.45 determine the friction on the trunk. d. Determine the net force on the trunk and the acceleration.
35 o