Answer:

Explanation:
In order to solve this question we need to know that
. Then we need to convert 4 minutes into seconds and cm into m. We can do that by multiplying the number of minutes by 60 (because there is 60 seconds in one minute) and dividing the number of cm by 100 (because there is 100 cm in one m). So.......
4min = 4 x 60s = 240s
300cm = 300/100 m = 3m
Now we know that distance = 300m, and that the time = 4min = 240s ⇒
⇒ 
Answer:
(a) the blocks all had different masses.
Explanation:
The surface is smooth, therefore coefficient of friction is tending to zero.
Forces for each blocks varied from 6N to 8N to 7N to 5N
The blocks were made of different materials and different materials are going to have varying weight for the same size of block.
Like charges repel, while opposite charges attract.
Answer:
99 V
Explanation:
The effective voltage of an AC current (also called rms voltage) is given by

where
Vrms is the rms voltage
V0 is the peak voltage
In this problem, we know the effective voltage:

Therefore, we can re-arrange the equation to find the peak voltage:

The correct answer is b changing tides