That would be c. :) :) :)
Impulse = (force) x (time)
The first impulse was (20 N) x (10 sec) = 200 meters/sec
The second one is (50 N) x (time) and we want it equal to the first one, so
(50 N) x (time) = 200 meters/sec
Divide each side by 50N : Time = 200/50 = <em>4 seconds</em>
By the way, the quantity we're playing with here is the cart's <em>momentum</em>.
Answer:
0.010 m
Explanation:
So the equation for a pendulum period is:
where L is the length of the pendulum. In this case I'll use the approximation of pi as 3.14, and g=9.8 m\s. So given that it oscillates once every 1.99 seconds. you have the equation:

Evaluate the multiplication in front

Divide both sides by 6.28

Square both sides

Multiply both sides by m/s^2 (the s^2 will cancel out)
Now now let's find the length when it's two seconds

Divide both sides by 6.28

Square both sides

Multiply both sides by 9.8 m/s^2 (s^2 will cancel out)

So to find the difference you simply subtract
0.984 - 0.994 = 0.010 m
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.