Answer:
Backwards
Explanation:
Friction always acts in the direction opposing motion so if the motion of the wagon is forward, friction acts backwards.
Answer:
Always wear safety goggles when performing an experiment.
Use caution when constructing the track.
Ensure that the track is clear before releasing cars.
Report all accidents to the teacher.Explanation:
Answer:
a) 
, b) 
Explanation:
a) The turntable has the following physical model by using Newton's laws:
The moment of inertia is:
b) The moment of inertia for a solid cylinder:
The mass of the turntable is:
Answer:
2 secs; 65 feet
Explanation:
The function guiding the water bottle is given as:
f(x) = -16t² + 64t + 1
The bottle will reach maximum height when velocity, df/dt (velocity is the first derivative of distance) = 0.
Therefore:
df/dt = 0 = -32t + 64
=> 32t = 64
t = 64/32 = 2 seconds
This is the time it will take to reach the maximum height.
To find this height, we insert t = 2 into the function f(x):
f = -16(2)² + 64(2) + 1
f = -(16 * 4) + 128 + 1
f = -64 + 128 + 1
f = 65 ft
Its maximum height is 65 ft.
Answer:C
Explanation:
Mass energy of hydrogen fusing into helium
