Answer:
the kinetic energy lost due to friction is 22.5 J
Explanation:
Given;
mass of the block, m = 0.2 kg
initial velocity of the block, u = 25 m/s
final velocity of the block, v = 20 m/s
The kinetic energy lost due to friction is calculated as;

Therefore, the kinetic energy lost due to friction is 22.5 J
the answer choice will be A because they travel at the same speed through only light not one material.
Answer:
2. 200N
3.50kg
4.700N
Explanation:
Weight is another word for the force of gravity
Weight is a force that acts at all times on all objects near Earth.
F=m*g
where g=acceleration due to gravity
2. due to the gravitational fields of the earth , assume gravitational acceleration=10m/s2
F=20*10= 200N
3.same as above
mass=Force/gravitational acceleration
mass=500/10 = 50kg
4.force=mass*gravitational acceleration
force=70*10=700N
Complete Question
The complete question is shown on the first uploaded image
Answer:
The velocity is
in positive x -direction
The speed is 
Explanation:
From the question we are told that
The distance from the house to truck is D = 20 m
The distance traveled back to retrieve wind-blown hat is d = 15
The distance from the wind-blown hat position too the truck is k = 20 m
The total time taken is t = 75 s
Generally when calculating the displacement the Justin's backward movement to collect his wind - blown hat is taken as negative
Generally Justin's displacement is mathematically represented as

=> 
Generally the average velocity is mathematically represented as

=> 
=>
Generally the distance covered by Justin is mathematically represented as

=> 
=> 
Generally Justin's average speed over a 75 s period is mathematically represented as

=> 
=> 