Practice Test 9 - 4th Grade Science
20 questions. Answer them in any order, then submit to see your score and every explanation.
- Based on these scenarios, which one demonstrates energy transfer by light? 1) Marcus rings a bell, and the sound travels down the hallway. 2) Yuki turns on a lamp, and the pages of her book look brighter. 3) Carlos holds his hands near a campfire and feels warmth. 4) Keisha plugs in a computer, and it powers on through the cord.
- Amir and Keisha see each other in a bright room. Explain how they are able to see one another.
- After floods, Yuki's class compares solutions. Solution A: levee (high effectiveness, high cost, long time). Solution B: elevate homes (moderate effectiveness, moderate cost, helps some). Solution C: wetlands (lower cost, needs space, moderate effectiveness). Using effectiveness and cost, which choice is the best tradeoff for many towns?
- In a safe bowling demo, Marcus rolls a bowling ball straight toward ten pins that are standing still. Before the collision, the ball is moving and the pins are not. After the ball hits, pins may fall and slide. Which question asks about energy changes in this collision?
- A forest town worries about wildfires during hot, dry summers. Solution A creates firebreaks (cleared strips with little vegetation) to slow fires, which can work well but needs regular clearing. Solution B uses fire-resistant building materials, which helps homes survive but can be expensive to remodel. Solution C installs early detection systems, like cameras and sensors, which can spot smoke quickly and send alerts, but it does not stop a fire by itself. Comparing these solutions using the criterion of maintenance needed each year, which solution likely needs the most maintenance?
- This wave model shows two arrows; which arrow shows the wavelength?
- At night, Carlos sees a road sign when car headlights shine on it. How does light make it possible to see the sign?
- Looking at this map, what pattern do you observe in where earthquakes are clustered?
- What is similar about how a cactus's spines and an armadillo's armor protect them?
- Two soccer balls are kicked on the field: Jamal's ball zooms to the cone in 3 s, and Emma's ball rolls slowly there in 9 s. Which ball has more kinetic energy (energy of motion)?
- Maya reads that flowing water turns turbines at a dam and produces electricity for towns. Based on this information, which statement correctly describes how water provides energy?
- When erosion happens along Keisha's riverbank, what can be an effect on people's homes?
- Fatima and Amir must send 8 different messages during a team game. Solution A uses claps (1 clap = "pass," 2 claps = "shoot," 3 claps = "guard," 4 claps = "switch," and more counts for more messages). Solution B uses a small set of 3 arm signals (point left, point right, hands on head) that can be combined. Comparing these solutions, which is better for the number of messages?
- Sofia makes two rope waves: one is tall with crests close; which description is correct?
- Based on this map, which area has the highest density of volcano symbols?
- Keisha measures wind erosion: strong wind moves 15 cm of sand in 1 hour, but a gentle breeze moves 1 cm. What happens when erosion occurs at a faster rate?
- In a 30-second running game, Keisha runs 90 m, and Carlos runs 45 m. Based on the scenario, who has more kinetic energy (energy of motion)?
- During silent reading, Emma and Jamal must share directions without speaking. Solution A uses hand gestures (1 finger up = "wait," 2 fingers = "come here," arms crossed = "stop"). Solution B uses desk taps (1 tap = "wait," 2 taps = "come here," 3 taps = "stop"). Comparing these solutions, which is better for secrecy in a quiet classroom?
- A glacier slowly moves rocks from a mountain valley to a pile near its melting edge. What evidence shows erosion?
- This scenario shows Emma warming her hands: campfire → heat through air → hands. Which correctly describes how energy moves?