Turn off standby appliances.
Install a smart thermostat.
Turn down your thermostat.
Buy efficient appliances.
Install a new boiler.
Wash clothes at a lower temperature.
Be smarter about water.
Invest in double glazing.
Answer:
c. testing student opinions
Explanation:
opinions aren't factual and they would not aide an experiment if it wasn't for a social experiment.
Answer:

Explanation:
Given that

We know that acceleration a given as




We know that



So the magnitude of force F

Answer:
Mass of larger cart will be 0.0213 m /sec
Explanation:
We have given mass of small cart 
Initial velocity of small cart 
Mass of larger block 
Initial velocity of larger cart 
After the collision velocity of smaller cart 
Now according conservation of momentum



