Force and Motion Unit Mighty Mustang Science Dept STAAR REVIEW

F=maForces Speed, Velocity & Acceleration Newton’s Laws

Row 1, Col 1 B. Force Which vocabulary word means a push or pull? A.Mass B.Force C.Acceleration D.Displacement

1,2 D. Speed Which vocabulary term means the rate at which an object moves? A. Mass B. Displacement C. Velocity D. Speed

1,3 D Velocity. Which vocabulary term means the speed and direction of a moving object? A Speed B Distance C Acceleration D Velocity

1,4 B. Inertia Which vocabulary term means the tendency to stay at rest or remain in motion? A. Speed B. Inertia C. Acceleration D. Newton

2,1 A. Acceleration Which vocabulary term means the rate at which speed or direction changes? A Acceleration B Speed C Velocity D Direction

2,2 D. Friction Which force resists the motion between two touching objects? A. Normal Force B. Air Resistance C. Gravity D. Friction

D. The direction of motion must be specified for velocity, but not for speed. 2,3 What is the difference between speed of a moving object and its velocity? A. The speed of a moving object never changes, but the velocity can change. B. The velocity of a moving object never changes, but the speed can change. C. The direction of motion must be specified for speed, but not for velocity. D. The direction of motion must be specified for velocity, but not for speed.

2,4 A. The more weight an object hast the more speed the object will have A student performed an investigation to measure speed. Above are the results from his investigation. What conclusion can be made about a falling object? A. The more weight an object hast the more speed the object will have B. The more weight an object has the less speed the object will have C. The less weight an object has the more speed the object will have D. The less weight an object has the more balanced an object is. Trial 1Trial 2Trial 3Trial 4 Helicopter Helicopter + 1 paperclip Helicopter + 2 paperclips Helicopter + 3 paperclips Time for Helicopter to Fall (sec)

3,1 D 50N to the Left A sailboat comes with an outboard motor which applies a force of 75N. A gust of wind applies a force of 25N to the sailboat. What is the net force and direction of the movement if the water exerts a force of 50N? A 150N to the Right B 150N to the Left C 50N to the Right D 50N to the Left 25N 75N 50N

3,2 C. Unbalanced forces cause an object to start moving, stop moving, or change directions. What do unbalanced forces do to an object when they act upon the object? A. Unbalanced forces cause an object to maintain its state of motion B. Unbalanced forces cause the net force of an object to be zero. C. Unbalanced forces cause an object to start moving, stop moving, or change directions. D. Unbalanced forces cause an object to maintain the same speed and same direction.

3,3 C. 100 cm/sec north The positions of the toy cat at three different times are labeled (1), (2), and (3). What is the velocity of the toy car at position (2)? A. 100 cm/sec B. 100 cm/sec 2 C. 100 cm/sec north D. 100 cm/sec 2 north

3,4 A squid moves through the water by ejecting water out of its body into the surrounding water. When the water is pushed out, the ejected water pushes back and thrusts the squid forward. Which of Newton’s laws of motion best applied to a squid’s movement through water? A. First law of motion B. Second law of motion C. Third law of motion D. Fourth law of motion C. Third law of motion

4,1 D. 80N A 40-kilogram student on an inner tube is pulled by a boat. The force from the boat results in the student acceleration at 2 m/s 2. The unit for measuring force is a Newton (N), which is equivalent to 1kgm/s 2. Using Newton’s second law of motion, calculate the net force needed to cause this acceleration. A 0.05N B 20N C 40N D 80N

4,2 B. X At what point should she let go of the string if she wants the yo-yo to roll directly away from her to her left? A. W B. X C. Y D. Z

4,3 B. The toy car’s speed has increased between the two positions What evidence shows that the toy car has accelerated between positions (1) and (2)? A. The toy car has moved. B. The toy car’s speed has increased between the two positions C. The toy car has come to a stop at position (3). D. The toy car’s direction of motion has changed.

4,4 C. A child and his sister push on a sofa from opposite sides. They are equally strong, and the sofa does not move in either direction. Which example best demonstrates an application of Newton’s first law of motion? A. A child tries to push a sofa across the floor, but it will not move. His sister comes to help him. Pushing together, the children are able to move the sofa. B. A child pushes two different sofas across the floor. He find that the light sofa is easier to push than the heavy sofa. C. A child and his sister push on a sofa from opposite sides. They are equally strong, and the sofa does not move in either direction. D. A child and his sister push two identical sofas across the floor in a race. His sister is stronger than he, and she wins the race.

5,1 D. Greater than 5.6 pounds. A string is attached to the front of a skateboard. Several bricks are placed on top of the skateboard so that the combined weight of the skateboard and bricks is 5.6 pounds. How much force must be applied to the string in order to move the skateboard forward? A Less than 5.6 pounds. B Equal to 5.6 pounds. C Greater than or equal to 5.6 pounds. D Greater than 5.6 pounds.

5,2 B. The unbalanced force caused the sailboat’s motion to increase from 0m/s to 0.5 m/s A young boy and his father put a toy sailboat on the surface of a pond. The boy is disappointed when the boat does not move. The boy gets down on his knees and blows into the sailboat’s sail. The father observes that the force from his son’s breath moves the sailboat one meter in two seconds. Which of the following statements describes how unbalanced forces changed the sailboats motion? A. The unbalanced force caused the sailboat’s motion to increase from 0m/s to 2 m/s B. The unbalanced force caused the sailboat’s motion to increase from 0m/s to 0.5 m/s C. The unbalanced force caused the sailboat’s motion to increase from 0m/s to 1m/s D. The unbalanced force caused the sailboat’s motion to decrease from 2m/s to 0m/s

5,3 A The direction of movement of the children on the Ferris wheel is constantly changing. The Ferris wheel is rotating at a constant speed. Why are the children riding the Ferris wheel accelerating? A The direction of movement of the children on the Ferris wheel is constantly changing. B The Ferris wheel’s speed remains constant. C The velocity of the Ferris wheel remains constant. D Any object that moves toward the ground must accelerate.

5,4 C. The skaters will move in the opposite direction from each other, but the skater with the lesser mass will move faster. Two skaters are standing on ice facing each other. The mass of one skater is twice the mass of the other skater. One skater pushes against the other skater. According to Newton’s second and third laws of motion, how will the skaters be affected by the push? A. The skaters will move in the opposite direction from each other, but the skater with the less mass will move backwards more slowly. B. The skaters will move in the opposite direction from each other at the same rate. C. The skaters will move in the opposite direction from each other, but the skater with the lesser mass will move faster. D. The skaters will move in the same direction, but the skater with the lesser mass will move faster.