A0.50-$kg$ block slides along a small track with elevated ends and a flat central part. the flat part has a length l = 1.00 $m$. the curved portions of the track are frictionless, but for the flat part the coefficient of kinetic friction is 0.144. the block is released from rest from a height h = 70 $cm$ on the left curved portion of the track. calculate the maximum height reached by the block on the right curved portion of the track.

y=55.6 cm

Explanation:

Given that

m=0.5 kg

L= 1 m

h= 70 cm = 0.7 m

coefficient of kinetic friction( μ ) = 0.144

Lets take maximum of height achieved by block on the right side

The friction force on the flat part

fr= μ  m g

Initial velocity at the top left is zero and the final speed of the bock at right top will be zero .

we know that work done by all force = Change in kinetic energy

Here initial and final speed is zero so the change in kinetic energy is zero.

m g h - fr . L - m g y=0

fr= μ  m g

m g h - μ  m g .L  - m g y=0

h - μ.L - y = 0

By putting the values

0.7 - 0.144 x 1 - y = 0

y=0.556 m

y=55.6 cm  

none, its a machine

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles