Answer:
Newton/square meters=70 AND Pascal=70
Explanation:
Formula:multiply the pressure value by 1.
It can't be less than 250 N or the cart wouldn't move at all. That means there is only 1 answer. It's between not enough info or 250 N. The answer is 250 N. If it was any more, there would be acceleration.
Answer:
current, only
Explanation:
current:I
voltage:U
resistance:R
formula: I=U/R
Increasing the battery cause the increasing in the voltage. Resistance does not normally change. And the current would increase.
Answer:

Explanation:
Using the conservation of energy we have:

Let's solve it for v:

So the speed at the lowest point is 
Now, using the conservation of momentum we have:

Therefore the speed of the block after the collision is 
I hope it helps you!
Answer:
The efficiency of Carnot's heat engine is 26.8 %.
Explanation:
Temperature of hot reservoir, TH = 100 degree C = 373 K
temperature of cold reservoir, Tc = 0 degree C = 273 K
The efficiency of Carnot's heat engine is
The efficiency of Carnot's heat engine is 26.8 %.