WorksheetsDebud Sec
Total questions: 10
Worksheet time: 10mins
Ken made a simple shooting game in Scratch. At the start, the bullets shoot normally. But after some time, the bullets stop coming out. When he presses the space bar, nothing happens. The image shows the script of the bullet.
What is the MOST likely reason the bullets stop firing after some time?
The bullets move too fast and go off screen
The clones are never deleted, and Scratch has a clone limit
The hide block prevents bullets from appearing
The create clone block can only be used once
Xiao Bei is making a simple shooting game. He wants the enemy's bullets to get faster over time. However, in his game right now:
-The bullets always move at the same speed (5)
-The bullets do not appear or move on the screen.
What should Xiao Bei do to fix the problem so that bullets appear and move faster over time?
Add a wait block inside the clone movement script
Reduce the wait time between clones
Change all of "my variable" block to "shooting speed" variable block， and move the code that controls the motion of bullet into when I start as a clone
script.
Use a different variable to control bullet speed for each clone
Simon is creating a flying bat game in Scratch. The bat is controlled using the arrow keys. He also created a custom block called `animation` to make the bat flap its wings. Image here shows part of his code.
Simon is having two problems:
1. The bat moves in the wrong direction. For example, pressing the down arrow moves it left.
2. The bat does not flap its wings when it moves.
What should Simon do to fix both problems?
Call the `animation` block inside each movement condition, and correct the movement directions by:
– changing down arrow to change y by -10 instead of x by -10
– changing left arrow to change x by -10 instead of y by -10
Replace the costumes with smaller bat images
Call the `animation` block once at the beginning of the project to start the animation loop, and correct the movement directions by:
– changing down arrow to change x by 10, and
– changing left arrow to change y by 10.
Use glide instead of change x/y for smoother movement.
Annie is creating a Scratch project that uses a list called “list 1”. Her goal is:
When the green flag is clicked, the list should be filled with numbers from 10 down to 1.
Then, every second, one item should be removed from the list, creating a countdown effect.
However, when she runs the program, list 1 remains empty and the countdown never starts.
Here is the core part of her code:
What should Annie do to fix the problem so the list is correctly filled and the countdown works?
Replace change list 1 by (length of list 1 + 1) with set list 1 to (length of list 1 + 1)
Replace change list 1 by (length of list 1 + 1) with insert (length of list 1 + 1) at 1 of list 1
Replace delete all of list 1 with add 1 to list 1
Change the repeat 10 loop to repeat until length of list 1 = 10
Ashley wants to keep track of the player's score at the end of each game round. She decides to store each score in a list called “ScoreHistory”.
Which of the following is the correct way for Ashley to create the “ScoreHistory” list in Scratch?
Go to the Variables category and click "Make a List"
Go to the Operators category and choose "Create List from Numbers"
Right-click on the score variable in the stage and choose "Convert to List"
Use the "when game ends" block to automatically generate a list from the score
Ashley wants to add a button to her Scratch project that clears all the data stored in the “ScoreHistory” list when clicked.
Which block should she use to completely remove all items from the “ScoreHistory” list?
delete 1 of ScoreHistory
remove all of ScoreHistory
clear ScoreHistory list
delete all of ScoreHistory
Ashley wrote the following code to make sure her “ScoreHistory” list never stores more than 10 scores:
However, this code doesn't work as expected. What is the main problem, and how should Ashley fix it?
The condition item 10 of ScoreHistory > 10 is invalid when the list has fewer than 10 items. She should check if length of ScoreHistory > 10 instead.
The delete 1 of ScoreHistory block should be replaced with delete last of ScoreHistory.
She should add a wait block inside the forever loop to prevent it from running too fast.
The list should be filled with zeros before running the forever loop.
Leon created an animation in Scratch where soldiers continuously walk out from a cave. Each soldier is supposed to gradually appear, starting from being fully transparent to fully visible. However, when he runs the project, the soldiers walk out, but the "fading in" effect does not appear.
Which of the following is the MOST LIKELY reason the effect is not working as intended?
The ghost effect is being increased instead of decreased, so the clone becomes more transparent instead of more visible.
The clone never appears because the show block is missing inside the clone’s script.
The original sprite is hidden, which prevents any clones from being created.
The create clone of myself block is placed inside a forever loop, which causes too many clones to be created at once.
Anthony is writing a Scratch program. His goal is to make sure that any negative number picked and stored in the variable “variable 1” is turned into a positive number.
However, when running the project, an error appears. What is the MOST LIKELY reason for the problem?
He used the asin() function instead of abs(), which does not convert negative numbers to positive ones.
The pick random block only picks positive numbers, so the asin() function receives invalid input.
The variable was never set before using asin(), so it contains nothing.
The say block cannot display the result of mathematical functions like asin() in Scratch.
Carol is trying to build a multiplication calculator in Scratch. She asks the user to input two numbers, stores them in variables “num1” and “num2”, and expects the sprite to say the result when the space key is pressed.
However, instead of multiplying the numbers, she uses this block in the “when space key pressed” script:
But when she runs the project and presses the space key, the sprite either says nothing or gives a strange result.
What is the BEST explanation of what went wrong?
She used the ln of operator, which is a logarithmic function, not multiplication.
The ln function can only be used with text, not numbers.
The answer block stores both “num1” and “num2” together, which cannot be used in calculations.
She used when space key pressed, which cannot trigger calculations in Scratch.
