Scientific Problem Solving
Balance
Velocity is speed and _______.
direction
What is the net force of 59 N → and ← 23 N?
36 N →
The rate at which the work is done is _____.
Power
[True/False] Nuclear Energy is an inexhaustible energy resource.
False
Change 507,000,000 into scientific notation
5.07 x 108
Acceleration is change in speed or change in ______.
direction
Newton’s second law allows scientists to calculate
Acceleration
If the input work to a machine is 100 J and the output work is 75 J, what is the efficiency of the machine?
75 %
Which energy resource is most abundant on Earth?
Solar Energy
[True/False] "Dating in 8th grade will affect the school grades." Is this a hypothesis?
True
When a car goes around a curve at a constant speed, in which direction is it accelerating?
towards the inside of the curve
"When one object exerts a force on a second object, the second object exerts an equal force in the opposite direction." The statement is Newton's _________ Law.
3rd
How does a broom stick make work easier?
Changing the distance of the force
Identify the energy transformations in a hydroelectric power plant.
potential energy->kinetic energy->mechanical(kinetic) energy->electrical energy
Comparing what you already know with the information you are given, in order to decide whether you agree with it
Critical Thinking
In the velocity-time graph Ms. Chung provided, in which section is there a negative velocity and a positive acceleration?
Section B
What is the acceleration if the following forces are applied to a 5 kg object: 20 N →; 50 N ↑; 50 N ↓; 30 N ←.
2 m/s2 ←
The second class lever has a mechanical advantage that is [bigger than/less than/equal to] 1.
bigger than
A 200-kg roller coaster cart is standing at the top of the hill with the energy of 8100 J. When the cart hits the ground, what is the velocity?
9 m/s
One grape is placed in tap water and another grape is placed in salt water. The change in their mass is measured after a day. What is the independent variable?
Type of water
In the distance-time graph Ms. Chung provided, what is the total distance?
200 meters
A 3-ton truck that was moving at 50m/s crashed into a 1-ton car that was at rest. It resulted in the car to move at 60m/s. What is the velocity of the truck after the car crash?
30 m/s
If the distance from the wheel to the handle in a wheelbarrow is 1.6m and to the load is 0.4m, how much input force is needed to lift a 200 N load?
50 N
What are two advantages of biomass?
1. it can be replaces as fast as it is used.
2. it can replace petroleum fuels in most vehicles.