A100-kg block is hanging on one side of the pulley 1.0-m off the floor while and unknown mass hangs on the other side. it takes 6.0-s for the 100-kg mass to reach the floor after being released from rest. what is the mass of the unknown block?

98,98 kg

Explanation:

We first need to calculate the acceleration the blocks needs to reach to the floor in 6 seconds. We can use the formula  where is initial velocity, a is acceleration, h is height and t is time. is zero since the block initially has zero velocity.

a = 1/2 * a * 6²

a= 0,05 m/s²

Then we will use the Newton’s second  law  to determine the net force on the system.  

Fnet=m.a

Fnet is net force and m is mass. We will use gravitational constant g as 9.81 m/s2 to find weights of the blocks then use them to find net force.

Fnet = 981 – 9,81m

981 – 9,81m = (100 + m)*0,05

976  = 9,86m

m = 98,98 kg

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