Answer:

Explanation:
According to the newton's second law of motion we can apply F=ma hear
Force = mass * acceleration
(assume the piano is moving left side )
←F = ma

Answer:
- 3 meter
Explanation:
A dog has started motion from +3 meter. ...(Given)
∴ maximum positive distance = + 3 meter
Magnitude of distance = 3
Maximum negative distance = (-) (magnitude of distance)
Maximum negative distance = (-) (3)
Maximum negative distance = -3 meter
Hence, maximum negative distance is -3 meter.
Solution:
Make an Observation - An indoor plant in a dark room withers faster than the same plant in a room with ample sunlight.
Ask a question- Why do certain indoor plants die faster based on where they are placed in the house?
State a hypothesis- Sunlight is probably essential for plants to grow and live.
Run an experiment- Get two potted plants. Cover one with black paper. Place both plants outside in sunlight. See what happens to each plant after one week.
Analyze the results-The plant in the pot with black paper withered. The other plant was healthy.
Communicate the results to others - Plants need sunlight to make food so they can live.
Answer:

Explanation:
Given data
velocity v₀=20 cm/s at time t=3s
velocity vf=0 at time t=8 s
To find
Average Acceleration at time=3s to 8s
Solution
As we know that acceleration is first derivative of velocity with respect to time
Incomplete question.The complete question is here
What is the magnitude of the force needed to hold the outer 2 cm of the blade to the inner portion of the blade? The outer edge of the blade is 21 cm from the center of the blade, and the mass of the outer portion is 7.7 g. Even though the blade is 21cm long, the last 2cm should be treated as if they were at a point 20cm from the center of rotation.
Answer:
F= 0.034 N
Explanation:
Given Data
Outer=2 cm
Edge of blade=21 cm
Mass=7.7 g
Length of blade=21 cm
The last 2cm is treated as if they were at a point 20cm from the center of rotation
To Find
Force=?
Solution
Convert the given frequency to angular frequency
ω = 45 rpm * (2*pi rad / 1 rev) * (1 min / 60 s)
ω= 3/2*π rad/sec
Now to find centripetal force.
F = m×v²/r
F= m×ω²×r
Put the data
F = 0.0077 kg × (3/2×π rad/sec
)²× 0.20 m
F= 0.034 N